2478 lines
75 KiB
C
2478 lines
75 KiB
C
/*
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* MPEG Audio decoder
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* Copyright (c) 2001, 2002 Fabrice Bellard.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* Modified heavily by Matt Campbell <mattcampbell@pobox.com> for the
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* stand-alone mpaudec library. Based on mpegaudiodec.c from libavcodec.
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*/
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/*#define DEBUG*/
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#include "internal.h"
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#include "mpegaudio.h"
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#ifdef _MSC_VER
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#pragma warning(disable : 4244)
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#endif
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/*
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* TODO:
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* - in low precision mode, use more 16 bit multiplies in synth filter
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* - test lsf / mpeg25 extensively.
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*/
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/* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg
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audio decoder */
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#define USE_HIGHPRECISION
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#ifdef USE_HIGHPRECISION
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#define FRAC_BITS 23 /* fractional bits for sb_samples and dct */
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#define WFRAC_BITS 16 /* fractional bits for window */
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#else
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#define FRAC_BITS 15 /* fractional bits for sb_samples and dct */
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#define WFRAC_BITS 14 /* fractional bits for window */
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#endif
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#define FRAC_ONE (1 << FRAC_BITS)
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#define MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> FRAC_BITS)
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#define MUL64(a,b) ((int64_t)(a) * (int64_t)(b))
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#define FIX(a) ((int)((a) * FRAC_ONE))
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/* WARNING: only correct for posititive numbers */
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#define FIXR(a) ((int)((a) * FRAC_ONE + 0.5))
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#define FRAC_RND(a) (((a) + (FRAC_ONE/2)) >> FRAC_BITS)
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#if FRAC_BITS <= 15
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typedef int16_t MPA_INT;
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#else
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typedef int32_t MPA_INT;
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#endif
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/****************/
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#define HEADER_SIZE 4
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#define BACKSTEP_SIZE 512
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typedef struct MPADecodeContext {
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uint8_t inbuf1[2][MPA_MAX_CODED_FRAME_SIZE + BACKSTEP_SIZE]; /* input buffer */
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int inbuf_index;
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uint8_t *inbuf_ptr, *inbuf;
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int frame_size;
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int free_format_frame_size; /* frame size in case of free format
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(zero if currently unknown) */
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/* next header (used in free format parsing) */
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int error_protection;
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int layer;
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int sample_rate;
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int sample_rate_index; /* between 0 and 8 */
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int bit_rate;
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int old_frame_size;
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GetBitContext gb;
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int nb_channels;
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int mode;
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int mode_ext;
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int lsf;
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MPA_INT synth_buf[MPA_MAX_CHANNELS][512 * 2];
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int synth_buf_offset[MPA_MAX_CHANNELS];
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int32_t sb_samples[MPA_MAX_CHANNELS][36][SBLIMIT];
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int32_t mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
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#ifdef DEBUG
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int frame_count;
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#endif
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} MPADecodeContext;
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/* layer 3 "granule" */
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typedef struct GranuleDef {
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uint8_t scfsi;
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int part2_3_length;
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int big_values;
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int global_gain;
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int scalefac_compress;
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uint8_t block_type;
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uint8_t switch_point;
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int table_select[3];
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int subblock_gain[3];
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uint8_t scalefac_scale;
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uint8_t count1table_select;
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int region_size[3]; /* number of huffman codes in each region */
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int preflag;
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int short_start, long_end; /* long/short band indexes */
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uint8_t scale_factors[40];
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int32_t sb_hybrid[SBLIMIT * 18]; /* 576 samples */
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} GranuleDef;
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#define MODE_EXT_MS_STEREO 2
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#define MODE_EXT_I_STEREO 1
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/* layer 3 huffman tables */
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typedef struct HuffTable {
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int xsize;
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const uint8_t *bits;
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const uint16_t *codes;
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} HuffTable;
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#include "mpaudectab.h"
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/* vlc structure for decoding layer 3 huffman tables */
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static VLC huff_vlc[16];
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static uint8_t *huff_code_table[16];
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static VLC huff_quad_vlc[2];
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/* computed from band_size_long */
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static uint16_t band_index_long[9][23];
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/* XXX: free when all decoders are closed */
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#define TABLE_4_3_SIZE (8191 + 16)
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static int8_t table_4_3_exp[TABLE_4_3_SIZE];
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#if FRAC_BITS <= 15
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static uint16_t table_4_3_value[TABLE_4_3_SIZE];
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#else
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static uint32_t table_4_3_value[TABLE_4_3_SIZE];
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#endif
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/* intensity stereo coef table */
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static int32_t is_table[2][16];
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static int32_t is_table_lsf[2][2][16];
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static int32_t csa_table[8][2];
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static int32_t mdct_win[8][36];
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/* lower 2 bits: modulo 3, higher bits: shift */
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static uint16_t scale_factor_modshift[64];
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/* [i][j]: 2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
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static int32_t scale_factor_mult[15][3];
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/* mult table for layer 2 group quantization */
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#define SCALE_GEN(v) \
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{ FIXR(1.0 * (v)), FIXR(0.7937005259 * (v)), FIXR(0.6299605249 * (v)) }
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static int32_t scale_factor_mult2[3][3] = {
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SCALE_GEN(4.0 / 3.0), /* 3 steps */
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SCALE_GEN(4.0 / 5.0), /* 5 steps */
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SCALE_GEN(4.0 / 9.0), /* 9 steps */
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};
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/* 2^(n/4) */
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static uint32_t scale_factor_mult3[4] = {
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FIXR(1.0),
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FIXR(1.18920711500272106671),
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FIXR(1.41421356237309504880),
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FIXR(1.68179283050742908605),
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};
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static MPA_INT window[512];
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/* layer 1 unscaling */
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/* n = number of bits of the mantissa minus 1 */
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static int l1_unscale(int n, int mant, int scale_factor)
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{
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int shift, mod;
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int64_t val;
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shift = scale_factor_modshift[scale_factor];
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mod = shift & 3;
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shift >>= 2;
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val = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]);
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shift += n;
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/* NOTE: at this point, 1 <= shift >= 21 + 15 */
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return (int)((val + ((int64_t)(1) << (shift - 1))) >> shift);
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}
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static int l2_unscale_group(int steps, int mant, int scale_factor)
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{
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int shift, mod, val;
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shift = scale_factor_modshift[scale_factor];
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mod = shift & 3;
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shift >>= 2;
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val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
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/* NOTE: at this point, 0 <= shift <= 21 */
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if (shift > 0)
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val = (val + (1 << (shift - 1))) >> shift;
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return val;
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}
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/* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
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static int l3_unscale(int value, int exponent)
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{
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#if FRAC_BITS <= 15
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unsigned int m;
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#else
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uint64_t m;
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#endif
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int e;
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e = table_4_3_exp[value];
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e += (exponent >> 2);
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e = FRAC_BITS - e;
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#if FRAC_BITS <= 15
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if (e > 31)
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e = 31;
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#endif
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m = table_4_3_value[value];
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#if FRAC_BITS <= 15
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m = (m * scale_factor_mult3[exponent & 3]);
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m = (m + (1 << (e-1))) >> e;
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return m;
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#else
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m = MUL64(m, scale_factor_mult3[exponent & 3]);
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m = (m + ((uint64_t)(1) << (e-1))) >> e;
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return (int)m;
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#endif
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}
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/* all integer n^(4/3) computation code */
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#define DEV_ORDER 13
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#define POW_FRAC_BITS 24
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#define POW_FRAC_ONE (1 << POW_FRAC_BITS)
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#define POW_FIX(a) ((int)((a) * POW_FRAC_ONE))
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#define POW_MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> POW_FRAC_BITS)
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static int dev_4_3_coefs[DEV_ORDER];
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static int pow_mult3[3] = {
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POW_FIX(1.0),
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POW_FIX(1.25992104989487316476),
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POW_FIX(1.58740105196819947474),
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};
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static void int_pow_init(void)
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{
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int i, a;
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a = POW_FIX(1.0);
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for(i=0;i<DEV_ORDER;i++) {
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a = POW_MULL(a, POW_FIX(4.0 / 3.0) - i * POW_FIX(1.0)) / (i + 1);
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dev_4_3_coefs[i] = a;
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}
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}
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/* return the mantissa and the binary exponent */
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static int int_pow(int i, int *exp_ptr)
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{
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int e, er, eq, j;
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int a, a1;
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/* renormalize */
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a = i;
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e = POW_FRAC_BITS;
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while (a < (1 << (POW_FRAC_BITS - 1))) {
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a = a << 1;
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e--;
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}
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a -= (1 << POW_FRAC_BITS);
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a1 = 0;
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for(j = DEV_ORDER - 1; j >= 0; j--)
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a1 = POW_MULL(a, dev_4_3_coefs[j] + a1);
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a = (1 << POW_FRAC_BITS) + a1;
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/* exponent compute (exact) */
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e = e * 4;
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er = e % 3;
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eq = e / 3;
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a = POW_MULL(a, pow_mult3[er]);
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while (a >= 2 * POW_FRAC_ONE) {
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a = a >> 1;
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eq++;
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}
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/* convert to float */
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while (a < POW_FRAC_ONE) {
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a = a << 1;
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eq--;
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}
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/* now POW_FRAC_ONE <= a < 2 * POW_FRAC_ONE */
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#if POW_FRAC_BITS > FRAC_BITS
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a = (a + (1 << (POW_FRAC_BITS - FRAC_BITS - 1))) >> (POW_FRAC_BITS - FRAC_BITS);
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/* correct overflow */
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if (a >= 2 * (1 << FRAC_BITS)) {
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a = a >> 1;
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eq++;
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}
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#endif
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*exp_ptr = eq;
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return a;
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}
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int mpaudec_init(MPAuDecContext * mpctx)
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{
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MPADecodeContext *s;
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static int init=0;
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int i, j, k;
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assert(mpctx != NULL);
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memset(mpctx, 0, sizeof(MPAuDecContext));
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mpctx->priv_data = calloc(1, sizeof(MPADecodeContext));
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if (mpctx->priv_data == NULL)
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return -1;
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s = mpctx->priv_data;
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if (!init && !mpctx->parse_only) {
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/* scale factors table for layer 1/2 */
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for(i=0;i<64;i++) {
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int shift, mod;
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/* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
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shift = (i / 3);
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mod = i % 3;
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scale_factor_modshift[i] = mod | (shift << 2);
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}
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/* scale factor multiply for layer 1 */
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for(i=0;i<15;i++) {
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int n, norm;
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n = i + 2;
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norm = (((int64_t)(1) << n) * FRAC_ONE) / ((1 << n) - 1);
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scale_factor_mult[i][0] = MULL(FIXR(1.0 * 2.0), norm);
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scale_factor_mult[i][1] = MULL(FIXR(0.7937005259 * 2.0), norm);
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scale_factor_mult[i][2] = MULL(FIXR(0.6299605249 * 2.0), norm);
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#ifdef DEBUG
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printf("%d: norm=%x s=%x %x %x\n",
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i, norm,
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scale_factor_mult[i][0],
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scale_factor_mult[i][1],
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scale_factor_mult[i][2]);
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#endif
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}
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/* window */
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/* max = 18760, max sum over all 16 coefs : 44736 */
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for(i=0;i<257;i++) {
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int v;
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v = mpa_enwindow[i];
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#if WFRAC_BITS < 16
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v = (v + (1 << (16 - WFRAC_BITS - 1))) >> (16 - WFRAC_BITS);
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#endif
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window[i] = v;
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if ((i & 63) != 0)
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v = -v;
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if (i != 0)
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window[512 - i] = v;
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}
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/* huffman decode tables */
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huff_code_table[0] = NULL;
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for(i=1;i<16;i++) {
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const HuffTable *h = &mpa_huff_tables[i];
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int xsize, x, y;
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unsigned int n;
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uint8_t *code_table;
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xsize = h->xsize;
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n = xsize * xsize;
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/* XXX: fail test */
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init_vlc(&huff_vlc[i], 8, n,
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h->bits, 1, 1, h->codes, 2, 2);
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code_table = calloc(n, 1);
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j = 0;
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for(x=0;x<xsize;x++) {
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for(y=0;y<xsize;y++)
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code_table[j++] = (x << 4) | y;
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}
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huff_code_table[i] = code_table;
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}
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for(i=0;i<2;i++) {
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init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,
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mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1);
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}
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for(i=0;i<9;i++) {
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k = 0;
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for(j=0;j<22;j++) {
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band_index_long[i][j] = k;
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k += band_size_long[i][j];
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}
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band_index_long[i][22] = k;
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}
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/* compute n ^ (4/3) and store it in mantissa/exp format */
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int_pow_init();
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for(i=1;i<TABLE_4_3_SIZE;i++) {
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int e, m;
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m = int_pow(i, &e);
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/* normalized to FRAC_BITS */
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table_4_3_value[i] = m;
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table_4_3_exp[i] = e;
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}
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for(i=0;i<7;i++) {
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float f;
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int v;
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if (i != 6) {
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f = tan((double)i * M_PI / 12.0);
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v = FIXR(f / (1.0 + f));
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} else {
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v = FIXR(1.0);
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}
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is_table[0][i] = v;
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is_table[1][6 - i] = v;
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}
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/* invalid values */
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for(i=7;i<16;i++)
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is_table[0][i] = is_table[1][i] = 0.0;
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for(i=0;i<16;i++) {
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double f;
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int e, k;
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for(j=0;j<2;j++) {
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e = -(j + 1) * ((i + 1) >> 1);
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f = pow(2.0, e / 4.0);
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k = i & 1;
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is_table_lsf[j][k ^ 1][i] = FIXR(f);
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is_table_lsf[j][k][i] = FIXR(1.0);
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#ifdef DEBUG
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printf("is_table_lsf %d %d: %x %x\n",
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i, j, is_table_lsf[j][0][i], is_table_lsf[j][1][i]);
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#endif
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}
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}
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for(i=0;i<8;i++) {
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float ci, cs, ca;
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ci = ci_table[i];
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cs = 1.0 / sqrt(1.0 + ci * ci);
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ca = cs * ci;
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csa_table[i][0] = FIX(cs);
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csa_table[i][1] = FIX(ca);
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}
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/* compute mdct windows */
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for(i=0;i<36;i++) {
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int v;
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v = FIXR(sin(M_PI * (i + 0.5) / 36.0));
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mdct_win[0][i] = v;
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mdct_win[1][i] = v;
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mdct_win[3][i] = v;
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}
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for(i=0;i<6;i++) {
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mdct_win[1][18 + i] = FIXR(1.0);
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mdct_win[1][24 + i] = FIXR(sin(M_PI * ((i + 6) + 0.5) / 12.0));
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mdct_win[1][30 + i] = FIXR(0.0);
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mdct_win[3][i] = FIXR(0.0);
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mdct_win[3][6 + i] = FIXR(sin(M_PI * (i + 0.5) / 12.0));
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mdct_win[3][12 + i] = FIXR(1.0);
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}
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for(i=0;i<12;i++)
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mdct_win[2][i] = FIXR(sin(M_PI * (i + 0.5) / 12.0));
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/* NOTE: we do frequency inversion adter the MDCT by changing
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the sign of the right window coefs */
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for(j=0;j<4;j++) {
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for(i=0;i<36;i+=2) {
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mdct_win[j + 4][i] = mdct_win[j][i];
|
|
mdct_win[j + 4][i + 1] = -mdct_win[j][i + 1];
|
|
}
|
|
}
|
|
|
|
#if defined(DEBUG)
|
|
for(j=0;j<8;j++) {
|
|
printf("win%d=\n", j);
|
|
for(i=0;i<36;i++)
|
|
printf("%f, ", (double)mdct_win[j][i] / FRAC_ONE);
|
|
printf("\n");
|
|
}
|
|
#endif
|
|
init = 1;
|
|
}
|
|
|
|
s->inbuf_index = 0;
|
|
s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
|
|
s->inbuf_ptr = s->inbuf;
|
|
#ifdef DEBUG
|
|
s->frame_count = 0;
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
/* tab[i][j] = 1.0 / (2.0 * cos(pi*(2*k+1) / 2^(6 - j))) */
|
|
|
|
/* cos(i*pi/64) */
|
|
|
|
#define COS0_0 FIXR(0.50060299823519630134)
|
|
#define COS0_1 FIXR(0.50547095989754365998)
|
|
#define COS0_2 FIXR(0.51544730992262454697)
|
|
#define COS0_3 FIXR(0.53104259108978417447)
|
|
#define COS0_4 FIXR(0.55310389603444452782)
|
|
#define COS0_5 FIXR(0.58293496820613387367)
|
|
#define COS0_6 FIXR(0.62250412303566481615)
|
|
#define COS0_7 FIXR(0.67480834145500574602)
|
|
#define COS0_8 FIXR(0.74453627100229844977)
|
|
#define COS0_9 FIXR(0.83934964541552703873)
|
|
#define COS0_10 FIXR(0.97256823786196069369)
|
|
#define COS0_11 FIXR(1.16943993343288495515)
|
|
#define COS0_12 FIXR(1.48416461631416627724)
|
|
#define COS0_13 FIXR(2.05778100995341155085)
|
|
#define COS0_14 FIXR(3.40760841846871878570)
|
|
#define COS0_15 FIXR(10.19000812354805681150)
|
|
|
|
#define COS1_0 FIXR(0.50241928618815570551)
|
|
#define COS1_1 FIXR(0.52249861493968888062)
|
|
#define COS1_2 FIXR(0.56694403481635770368)
|
|
#define COS1_3 FIXR(0.64682178335999012954)
|
|
#define COS1_4 FIXR(0.78815462345125022473)
|
|
#define COS1_5 FIXR(1.06067768599034747134)
|
|
#define COS1_6 FIXR(1.72244709823833392782)
|
|
#define COS1_7 FIXR(5.10114861868916385802)
|
|
|
|
#define COS2_0 FIXR(0.50979557910415916894)
|
|
#define COS2_1 FIXR(0.60134488693504528054)
|
|
#define COS2_2 FIXR(0.89997622313641570463)
|
|
#define COS2_3 FIXR(2.56291544774150617881)
|
|
|
|
#define COS3_0 FIXR(0.54119610014619698439)
|
|
#define COS3_1 FIXR(1.30656296487637652785)
|
|
|
|
#define COS4_0 FIXR(0.70710678118654752439)
|
|
|
|
/* butterfly operator */
|
|
#define BF(a, b, c)\
|
|
{\
|
|
tmp0 = tab[a] + tab[b];\
|
|
tmp1 = tab[a] - tab[b];\
|
|
tab[a] = tmp0;\
|
|
tab[b] = MULL(tmp1, c);\
|
|
}
|
|
|
|
#define BF1(a, b, c, d)\
|
|
{\
|
|
BF(a, b, COS4_0);\
|
|
BF(c, d, -COS4_0);\
|
|
tab[c] += tab[d];\
|
|
}
|
|
|
|
#define BF2(a, b, c, d)\
|
|
{\
|
|
BF(a, b, COS4_0);\
|
|
BF(c, d, -COS4_0);\
|
|
tab[c] += tab[d];\
|
|
tab[a] += tab[c];\
|
|
tab[c] += tab[b];\
|
|
tab[b] += tab[d];\
|
|
}
|
|
|
|
#define ADD(a, b) tab[a] += tab[b]
|
|
|
|
/* DCT32 without 1/sqrt(2) coef zero scaling. */
|
|
static void dct32(int32_t *out, int32_t *tab)
|
|
{
|
|
int tmp0, tmp1;
|
|
|
|
/* pass 1 */
|
|
BF(0, 31, COS0_0);
|
|
BF(1, 30, COS0_1);
|
|
BF(2, 29, COS0_2);
|
|
BF(3, 28, COS0_3);
|
|
BF(4, 27, COS0_4);
|
|
BF(5, 26, COS0_5);
|
|
BF(6, 25, COS0_6);
|
|
BF(7, 24, COS0_7);
|
|
BF(8, 23, COS0_8);
|
|
BF(9, 22, COS0_9);
|
|
BF(10, 21, COS0_10);
|
|
BF(11, 20, COS0_11);
|
|
BF(12, 19, COS0_12);
|
|
BF(13, 18, COS0_13);
|
|
BF(14, 17, COS0_14);
|
|
BF(15, 16, COS0_15);
|
|
|
|
/* pass 2 */
|
|
BF(0, 15, COS1_0);
|
|
BF(1, 14, COS1_1);
|
|
BF(2, 13, COS1_2);
|
|
BF(3, 12, COS1_3);
|
|
BF(4, 11, COS1_4);
|
|
BF(5, 10, COS1_5);
|
|
BF(6, 9, COS1_6);
|
|
BF(7, 8, COS1_7);
|
|
|
|
BF(16, 31, -COS1_0);
|
|
BF(17, 30, -COS1_1);
|
|
BF(18, 29, -COS1_2);
|
|
BF(19, 28, -COS1_3);
|
|
BF(20, 27, -COS1_4);
|
|
BF(21, 26, -COS1_5);
|
|
BF(22, 25, -COS1_6);
|
|
BF(23, 24, -COS1_7);
|
|
|
|
/* pass 3 */
|
|
BF(0, 7, COS2_0);
|
|
BF(1, 6, COS2_1);
|
|
BF(2, 5, COS2_2);
|
|
BF(3, 4, COS2_3);
|
|
|
|
BF(8, 15, -COS2_0);
|
|
BF(9, 14, -COS2_1);
|
|
BF(10, 13, -COS2_2);
|
|
BF(11, 12, -COS2_3);
|
|
|
|
BF(16, 23, COS2_0);
|
|
BF(17, 22, COS2_1);
|
|
BF(18, 21, COS2_2);
|
|
BF(19, 20, COS2_3);
|
|
|
|
BF(24, 31, -COS2_0);
|
|
BF(25, 30, -COS2_1);
|
|
BF(26, 29, -COS2_2);
|
|
BF(27, 28, -COS2_3);
|
|
|
|
/* pass 4 */
|
|
BF(0, 3, COS3_0);
|
|
BF(1, 2, COS3_1);
|
|
|
|
BF(4, 7, -COS3_0);
|
|
BF(5, 6, -COS3_1);
|
|
|
|
BF(8, 11, COS3_0);
|
|
BF(9, 10, COS3_1);
|
|
|
|
BF(12, 15, -COS3_0);
|
|
BF(13, 14, -COS3_1);
|
|
|
|
BF(16, 19, COS3_0);
|
|
BF(17, 18, COS3_1);
|
|
|
|
BF(20, 23, -COS3_0);
|
|
BF(21, 22, -COS3_1);
|
|
|
|
BF(24, 27, COS3_0);
|
|
BF(25, 26, COS3_1);
|
|
|
|
BF(28, 31, -COS3_0);
|
|
BF(29, 30, -COS3_1);
|
|
|
|
/* pass 5 */
|
|
BF1(0, 1, 2, 3);
|
|
BF2(4, 5, 6, 7);
|
|
BF1(8, 9, 10, 11);
|
|
BF2(12, 13, 14, 15);
|
|
BF1(16, 17, 18, 19);
|
|
BF2(20, 21, 22, 23);
|
|
BF1(24, 25, 26, 27);
|
|
BF2(28, 29, 30, 31);
|
|
|
|
/* pass 6 */
|
|
|
|
ADD( 8, 12);
|
|
ADD(12, 10);
|
|
ADD(10, 14);
|
|
ADD(14, 9);
|
|
ADD( 9, 13);
|
|
ADD(13, 11);
|
|
ADD(11, 15);
|
|
|
|
out[ 0] = tab[0];
|
|
out[16] = tab[1];
|
|
out[ 8] = tab[2];
|
|
out[24] = tab[3];
|
|
out[ 4] = tab[4];
|
|
out[20] = tab[5];
|
|
out[12] = tab[6];
|
|
out[28] = tab[7];
|
|
out[ 2] = tab[8];
|
|
out[18] = tab[9];
|
|
out[10] = tab[10];
|
|
out[26] = tab[11];
|
|
out[ 6] = tab[12];
|
|
out[22] = tab[13];
|
|
out[14] = tab[14];
|
|
out[30] = tab[15];
|
|
|
|
ADD(24, 28);
|
|
ADD(28, 26);
|
|
ADD(26, 30);
|
|
ADD(30, 25);
|
|
ADD(25, 29);
|
|
ADD(29, 27);
|
|
ADD(27, 31);
|
|
|
|
out[ 1] = tab[16] + tab[24];
|
|
out[17] = tab[17] + tab[25];
|
|
out[ 9] = tab[18] + tab[26];
|
|
out[25] = tab[19] + tab[27];
|
|
out[ 5] = tab[20] + tab[28];
|
|
out[21] = tab[21] + tab[29];
|
|
out[13] = tab[22] + tab[30];
|
|
out[29] = tab[23] + tab[31];
|
|
out[ 3] = tab[24] + tab[20];
|
|
out[19] = tab[25] + tab[21];
|
|
out[11] = tab[26] + tab[22];
|
|
out[27] = tab[27] + tab[23];
|
|
out[ 7] = tab[28] + tab[18];
|
|
out[23] = tab[29] + tab[19];
|
|
out[15] = tab[30] + tab[17];
|
|
out[31] = tab[31];
|
|
}
|
|
|
|
#define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 15)
|
|
|
|
#if FRAC_BITS <= 15
|
|
|
|
static int round_sample(int sum)
|
|
{
|
|
int sum1;
|
|
sum1 = (sum + (1 << (OUT_SHIFT - 1))) >> OUT_SHIFT;
|
|
if (sum1 < -32768)
|
|
sum1 = -32768;
|
|
else if (sum1 > 32767)
|
|
sum1 = 32767;
|
|
return sum1;
|
|
}
|
|
|
|
/* signed 16x16 -> 32 multiply add accumulate */
|
|
#define MACS(rt, ra, rb) rt += (ra) * (rb)
|
|
|
|
/* signed 16x16 -> 32 multiply */
|
|
#define MULS(ra, rb) ((ra) * (rb))
|
|
|
|
#else
|
|
|
|
static int round_sample(int64_t sum)
|
|
{
|
|
int sum1;
|
|
sum1 = (int)((sum + ((int64_t)(1) << (OUT_SHIFT - 1))) >> OUT_SHIFT);
|
|
if (sum1 < -32768)
|
|
sum1 = -32768;
|
|
else if (sum1 > 32767)
|
|
sum1 = 32767;
|
|
return sum1;
|
|
}
|
|
|
|
#define MULS(ra, rb) MUL64(ra, rb)
|
|
|
|
#endif
|
|
|
|
#define SUM8(sum, op, w, p) \
|
|
{ \
|
|
sum op MULS((w)[0 * 64], p[0 * 64]);\
|
|
sum op MULS((w)[1 * 64], p[1 * 64]);\
|
|
sum op MULS((w)[2 * 64], p[2 * 64]);\
|
|
sum op MULS((w)[3 * 64], p[3 * 64]);\
|
|
sum op MULS((w)[4 * 64], p[4 * 64]);\
|
|
sum op MULS((w)[5 * 64], p[5 * 64]);\
|
|
sum op MULS((w)[6 * 64], p[6 * 64]);\
|
|
sum op MULS((w)[7 * 64], p[7 * 64]);\
|
|
}
|
|
|
|
#define SUM8P2(sum1, op1, sum2, op2, w1, w2, p) \
|
|
{ \
|
|
int tmp;\
|
|
tmp = p[0 * 64];\
|
|
sum1 op1 MULS((w1)[0 * 64], tmp);\
|
|
sum2 op2 MULS((w2)[0 * 64], tmp);\
|
|
tmp = p[1 * 64];\
|
|
sum1 op1 MULS((w1)[1 * 64], tmp);\
|
|
sum2 op2 MULS((w2)[1 * 64], tmp);\
|
|
tmp = p[2 * 64];\
|
|
sum1 op1 MULS((w1)[2 * 64], tmp);\
|
|
sum2 op2 MULS((w2)[2 * 64], tmp);\
|
|
tmp = p[3 * 64];\
|
|
sum1 op1 MULS((w1)[3 * 64], tmp);\
|
|
sum2 op2 MULS((w2)[3 * 64], tmp);\
|
|
tmp = p[4 * 64];\
|
|
sum1 op1 MULS((w1)[4 * 64], tmp);\
|
|
sum2 op2 MULS((w2)[4 * 64], tmp);\
|
|
tmp = p[5 * 64];\
|
|
sum1 op1 MULS((w1)[5 * 64], tmp);\
|
|
sum2 op2 MULS((w2)[5 * 64], tmp);\
|
|
tmp = p[6 * 64];\
|
|
sum1 op1 MULS((w1)[6 * 64], tmp);\
|
|
sum2 op2 MULS((w2)[6 * 64], tmp);\
|
|
tmp = p[7 * 64];\
|
|
sum1 op1 MULS((w1)[7 * 64], tmp);\
|
|
sum2 op2 MULS((w2)[7 * 64], tmp);\
|
|
}
|
|
|
|
|
|
/* 32 sub band synthesis filter. Input: 32 sub band samples, Output:
|
|
32 samples. */
|
|
/* XXX: optimize by avoiding ring buffer usage */
|
|
static void synth_filter(MPADecodeContext *s1,
|
|
int ch, int16_t *samples, int incr,
|
|
int32_t sb_samples[SBLIMIT])
|
|
{
|
|
int32_t tmp[32];
|
|
MPA_INT *synth_buf;
|
|
const MPA_INT *w, *w2, *p;
|
|
int j, offset, v;
|
|
int16_t *samples2;
|
|
#if FRAC_BITS <= 15
|
|
int32_t sum, sum2;
|
|
#else
|
|
int64_t sum, sum2;
|
|
#endif
|
|
|
|
dct32(tmp, sb_samples);
|
|
|
|
offset = s1->synth_buf_offset[ch];
|
|
synth_buf = s1->synth_buf[ch] + offset;
|
|
|
|
for(j=0;j<32;j++) {
|
|
v = tmp[j];
|
|
#if FRAC_BITS <= 15
|
|
/* NOTE: can cause a loss in precision if very high amplitude
|
|
sound */
|
|
if (v > 32767)
|
|
v = 32767;
|
|
else if (v < -32768)
|
|
v = -32768;
|
|
#endif
|
|
synth_buf[j] = v;
|
|
}
|
|
/* copy to avoid wrap */
|
|
memcpy(synth_buf + 512, synth_buf, 32 * sizeof(MPA_INT));
|
|
|
|
samples2 = samples + 31 * incr;
|
|
w = window;
|
|
w2 = window + 31;
|
|
|
|
sum = 0;
|
|
p = synth_buf + 16;
|
|
SUM8(sum, +=, w, p);
|
|
p = synth_buf + 48;
|
|
SUM8(sum, -=, w + 32, p);
|
|
*samples = round_sample(sum);
|
|
samples += incr;
|
|
w++;
|
|
|
|
/* we calculate two samples at the same time to avoid one memory
|
|
access per two sample */
|
|
for(j=1;j<16;j++) {
|
|
sum = 0;
|
|
sum2 = 0;
|
|
p = synth_buf + 16 + j;
|
|
SUM8P2(sum, +=, sum2, -=, w, w2, p);
|
|
p = synth_buf + 48 - j;
|
|
SUM8P2(sum, -=, sum2, -=, w + 32, w2 + 32, p);
|
|
|
|
*samples = round_sample(sum);
|
|
samples += incr;
|
|
*samples2 = round_sample(sum2);
|
|
samples2 -= incr;
|
|
w++;
|
|
w2--;
|
|
}
|
|
|
|
p = synth_buf + 32;
|
|
sum = 0;
|
|
SUM8(sum, -=, w + 32, p);
|
|
*samples = round_sample(sum);
|
|
|
|
offset = (offset - 32) & 511;
|
|
s1->synth_buf_offset[ch] = offset;
|
|
}
|
|
|
|
/* cos(pi*i/24) */
|
|
#define C1 FIXR(0.99144486137381041114)
|
|
#define C3 FIXR(0.92387953251128675612)
|
|
#define C5 FIXR(0.79335334029123516458)
|
|
#define C7 FIXR(0.60876142900872063941)
|
|
#define C9 FIXR(0.38268343236508977173)
|
|
#define C11 FIXR(0.13052619222005159154)
|
|
|
|
/* 12 points IMDCT. We compute it "by hand" by factorizing obvious
|
|
cases. */
|
|
static void imdct12(int *out, int *in)
|
|
{
|
|
int tmp;
|
|
int64_t in1_3, in1_9, in4_3, in4_9;
|
|
|
|
in1_3 = MUL64(in[1], C3);
|
|
in1_9 = MUL64(in[1], C9);
|
|
in4_3 = MUL64(in[4], C3);
|
|
in4_9 = MUL64(in[4], C9);
|
|
|
|
tmp = FRAC_RND(MUL64(in[0], C7) - in1_3 - MUL64(in[2], C11) +
|
|
MUL64(in[3], C1) - in4_9 - MUL64(in[5], C5));
|
|
out[0] = tmp;
|
|
out[5] = -tmp;
|
|
tmp = FRAC_RND(MUL64(in[0] - in[3], C9) - in1_3 +
|
|
MUL64(in[2] + in[5], C3) - in4_9);
|
|
out[1] = tmp;
|
|
out[4] = -tmp;
|
|
tmp = FRAC_RND(MUL64(in[0], C11) - in1_9 + MUL64(in[2], C7) -
|
|
MUL64(in[3], C5) + in4_3 - MUL64(in[5], C1));
|
|
out[2] = tmp;
|
|
out[3] = -tmp;
|
|
tmp = FRAC_RND(MUL64(-in[0], C5) + in1_9 + MUL64(in[2], C1) +
|
|
MUL64(in[3], C11) - in4_3 - MUL64(in[5], C7));
|
|
out[6] = tmp;
|
|
out[11] = tmp;
|
|
tmp = FRAC_RND(MUL64(-in[0] + in[3], C3) - in1_9 +
|
|
MUL64(in[2] + in[5], C9) + in4_3);
|
|
out[7] = tmp;
|
|
out[10] = tmp;
|
|
tmp = FRAC_RND(-MUL64(in[0], C1) - in1_3 - MUL64(in[2], C5) -
|
|
MUL64(in[3], C7) - in4_9 - MUL64(in[5], C11));
|
|
out[8] = tmp;
|
|
out[9] = tmp;
|
|
}
|
|
|
|
#undef C1
|
|
#undef C3
|
|
#undef C5
|
|
#undef C7
|
|
#undef C9
|
|
#undef C11
|
|
|
|
/* cos(pi*i/18) */
|
|
#define C1 FIXR(0.98480775301220805936)
|
|
#define C2 FIXR(0.93969262078590838405)
|
|
#define C3 FIXR(0.86602540378443864676)
|
|
#define C4 FIXR(0.76604444311897803520)
|
|
#define C5 FIXR(0.64278760968653932632)
|
|
#define C6 FIXR(0.5)
|
|
#define C7 FIXR(0.34202014332566873304)
|
|
#define C8 FIXR(0.17364817766693034885)
|
|
|
|
/* 0.5 / cos(pi*(2*i+1)/36) */
|
|
static const int icos36[9] = {
|
|
FIXR(0.50190991877167369479),
|
|
FIXR(0.51763809020504152469),
|
|
FIXR(0.55168895948124587824),
|
|
FIXR(0.61038729438072803416),
|
|
FIXR(0.70710678118654752439),
|
|
FIXR(0.87172339781054900991),
|
|
FIXR(1.18310079157624925896),
|
|
FIXR(1.93185165257813657349),
|
|
FIXR(5.73685662283492756461),
|
|
};
|
|
|
|
static const int icos72[18] = {
|
|
/* 0.5 / cos(pi*(2*i+19)/72) */
|
|
FIXR(0.74009361646113053152),
|
|
FIXR(0.82133981585229078570),
|
|
FIXR(0.93057949835178895673),
|
|
FIXR(1.08284028510010010928),
|
|
FIXR(1.30656296487637652785),
|
|
FIXR(1.66275476171152078719),
|
|
FIXR(2.31011315767264929558),
|
|
FIXR(3.83064878777019433457),
|
|
FIXR(11.46279281302667383546),
|
|
|
|
/* 0.5 / cos(pi*(2*(i + 18) +19)/72) */
|
|
FIXR(-0.67817085245462840086),
|
|
FIXR(-0.63023620700513223342),
|
|
FIXR(-0.59284452371708034528),
|
|
FIXR(-0.56369097343317117734),
|
|
FIXR(-0.54119610014619698439),
|
|
FIXR(-0.52426456257040533932),
|
|
FIXR(-0.51213975715725461845),
|
|
FIXR(-0.50431448029007636036),
|
|
FIXR(-0.50047634258165998492),
|
|
};
|
|
|
|
/* using Lee like decomposition followed by hand coded 9 points DCT */
|
|
static void imdct36(int *out, int *in)
|
|
{
|
|
int i, j, t0, t1, t2, t3, s0, s1, s2, s3;
|
|
int tmp[18], *tmp1, *in1;
|
|
int64_t in3_3, in6_6;
|
|
|
|
for(i=17;i>=1;i--)
|
|
in[i] += in[i-1];
|
|
for(i=17;i>=3;i-=2)
|
|
in[i] += in[i-2];
|
|
|
|
for(j=0;j<2;j++) {
|
|
tmp1 = tmp + j;
|
|
in1 = in + j;
|
|
|
|
in3_3 = MUL64(in1[2*3], C3);
|
|
in6_6 = MUL64(in1[2*6], C6);
|
|
|
|
tmp1[0] = FRAC_RND(MUL64(in1[2*1], C1) + in3_3 +
|
|
MUL64(in1[2*5], C5) + MUL64(in1[2*7], C7));
|
|
tmp1[2] = in1[2*0] + FRAC_RND(MUL64(in1[2*2], C2) +
|
|
MUL64(in1[2*4], C4) + in6_6 +
|
|
MUL64(in1[2*8], C8));
|
|
tmp1[4] = FRAC_RND(MUL64(in1[2*1] - in1[2*5] - in1[2*7], C3));
|
|
tmp1[6] = FRAC_RND(MUL64(in1[2*2] - in1[2*4] - in1[2*8], C6)) -
|
|
in1[2*6] + in1[2*0];
|
|
tmp1[8] = FRAC_RND(MUL64(in1[2*1], C5) - in3_3 -
|
|
MUL64(in1[2*5], C7) + MUL64(in1[2*7], C1));
|
|
tmp1[10] = in1[2*0] + FRAC_RND(MUL64(-in1[2*2], C8) -
|
|
MUL64(in1[2*4], C2) + in6_6 +
|
|
MUL64(in1[2*8], C4));
|
|
tmp1[12] = FRAC_RND(MUL64(in1[2*1], C7) - in3_3 +
|
|
MUL64(in1[2*5], C1) -
|
|
MUL64(in1[2*7], C5));
|
|
tmp1[14] = in1[2*0] + FRAC_RND(MUL64(-in1[2*2], C4) +
|
|
MUL64(in1[2*4], C8) + in6_6 -
|
|
MUL64(in1[2*8], C2));
|
|
tmp1[16] = in1[2*0] - in1[2*2] + in1[2*4] - in1[2*6] + in1[2*8];
|
|
}
|
|
|
|
i = 0;
|
|
for(j=0;j<4;j++) {
|
|
t0 = tmp[i];
|
|
t1 = tmp[i + 2];
|
|
s0 = t1 + t0;
|
|
s2 = t1 - t0;
|
|
|
|
t2 = tmp[i + 1];
|
|
t3 = tmp[i + 3];
|
|
s1 = MULL(t3 + t2, icos36[j]);
|
|
s3 = MULL(t3 - t2, icos36[8 - j]);
|
|
|
|
t0 = MULL(s0 + s1, icos72[9 + 8 - j]);
|
|
t1 = MULL(s0 - s1, icos72[8 - j]);
|
|
out[18 + 9 + j] = t0;
|
|
out[18 + 8 - j] = t0;
|
|
out[9 + j] = -t1;
|
|
out[8 - j] = t1;
|
|
|
|
t0 = MULL(s2 + s3, icos72[9+j]);
|
|
t1 = MULL(s2 - s3, icos72[j]);
|
|
out[18 + 9 + (8 - j)] = t0;
|
|
out[18 + j] = t0;
|
|
out[9 + (8 - j)] = -t1;
|
|
out[j] = t1;
|
|
i += 4;
|
|
}
|
|
|
|
s0 = tmp[16];
|
|
s1 = MULL(tmp[17], icos36[4]);
|
|
t0 = MULL(s0 + s1, icos72[9 + 4]);
|
|
t1 = MULL(s0 - s1, icos72[4]);
|
|
out[18 + 9 + 4] = t0;
|
|
out[18 + 8 - 4] = t0;
|
|
out[9 + 4] = -t1;
|
|
out[8 - 4] = t1;
|
|
}
|
|
|
|
/* fast header check for resync */
|
|
static int check_header(uint32_t header)
|
|
{
|
|
/* header */
|
|
if ((header & 0xffe00000) != 0xffe00000)
|
|
return -1;
|
|
/* layer check */
|
|
if (((header >> 17) & 3) == 0)
|
|
return -1;
|
|
/* bit rate */
|
|
if (((header >> 12) & 0xf) == 0xf)
|
|
return -1;
|
|
/* frequency */
|
|
if (((header >> 10) & 3) == 3)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
/* header + layer + bitrate + freq + lsf/mpeg25 */
|
|
#define SAME_HEADER_MASK \
|
|
(0xffe00000 | (3 << 17) | (0xf << 12) | (3 << 10) | (3 << 19))
|
|
|
|
/* header decoding. MUST check the header before because no
|
|
consistency check is done there. Return 1 if free format found and
|
|
that the frame size must be computed externally */
|
|
static int decode_header(MPADecodeContext *s, uint32_t header)
|
|
{
|
|
int sample_rate, frame_size, mpeg25, padding;
|
|
int sample_rate_index, bitrate_index;
|
|
if (header & (1<<20)) {
|
|
s->lsf = (header & (1<<19)) ? 0 : 1;
|
|
mpeg25 = 0;
|
|
} else {
|
|
s->lsf = 1;
|
|
mpeg25 = 1;
|
|
}
|
|
|
|
s->layer = 4 - ((header >> 17) & 3);
|
|
/* extract frequency */
|
|
sample_rate_index = (header >> 10) & 3;
|
|
sample_rate = mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);
|
|
sample_rate_index += 3 * (s->lsf + mpeg25);
|
|
s->sample_rate_index = sample_rate_index;
|
|
s->error_protection = ((header >> 16) & 1) ^ 1;
|
|
s->sample_rate = sample_rate;
|
|
|
|
bitrate_index = (header >> 12) & 0xf;
|
|
padding = (header >> 9) & 1;
|
|
s->mode = (header >> 6) & 3;
|
|
s->mode_ext = (header >> 4) & 3;
|
|
|
|
if (s->mode == MPA_MONO)
|
|
s->nb_channels = 1;
|
|
else
|
|
s->nb_channels = 2;
|
|
|
|
if (bitrate_index != 0) {
|
|
frame_size = mpa_bitrate_tab[s->lsf][s->layer - 1][bitrate_index];
|
|
s->bit_rate = frame_size * 1000;
|
|
switch(s->layer) {
|
|
case 1:
|
|
frame_size = (frame_size * 12000) / sample_rate;
|
|
frame_size = (frame_size + padding) * 4;
|
|
break;
|
|
case 2:
|
|
frame_size = (frame_size * 144000) / sample_rate;
|
|
frame_size += padding;
|
|
break;
|
|
default:
|
|
case 3:
|
|
frame_size = (frame_size * 144000) / (sample_rate << s->lsf);
|
|
frame_size += padding;
|
|
break;
|
|
}
|
|
s->frame_size = frame_size;
|
|
} else {
|
|
/* if no frame size computed, signal it */
|
|
if (!s->free_format_frame_size)
|
|
return 1;
|
|
/* free format: compute bitrate and real frame size from the
|
|
frame size we extracted by reading the bitstream */
|
|
s->frame_size = s->free_format_frame_size;
|
|
switch(s->layer) {
|
|
case 1:
|
|
s->frame_size += padding * 4;
|
|
s->bit_rate = (s->frame_size * sample_rate) / 48000;
|
|
break;
|
|
case 2:
|
|
s->frame_size += padding;
|
|
s->bit_rate = (s->frame_size * sample_rate) / 144000;
|
|
break;
|
|
default:
|
|
case 3:
|
|
s->frame_size += padding;
|
|
s->bit_rate = (s->frame_size * (sample_rate << s->lsf)) / 144000;
|
|
break;
|
|
}
|
|
}
|
|
|
|
#if defined(DEBUG)
|
|
printf("layer%d, %d Hz, %d kbits/s, ",
|
|
s->layer, s->sample_rate, s->bit_rate);
|
|
if (s->nb_channels == 2) {
|
|
if (s->layer == 3) {
|
|
if (s->mode_ext & MODE_EXT_MS_STEREO)
|
|
printf("ms-");
|
|
if (s->mode_ext & MODE_EXT_I_STEREO)
|
|
printf("i-");
|
|
}
|
|
printf("stereo");
|
|
} else {
|
|
printf("mono");
|
|
}
|
|
printf("\n");
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
/* return the number of decoded frames */
|
|
static int mp_decode_layer1(MPADecodeContext *s)
|
|
{
|
|
int bound, i, v, n, ch, j, mant;
|
|
uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];
|
|
uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
|
|
|
|
if (s->mode == MPA_JSTEREO)
|
|
bound = (s->mode_ext + 1) * 4;
|
|
else
|
|
bound = SBLIMIT;
|
|
|
|
/* allocation bits */
|
|
for(i=0;i<bound;i++) {
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
allocation[ch][i] = get_bits(&s->gb, 4);
|
|
}
|
|
}
|
|
for(i=bound;i<SBLIMIT;i++) {
|
|
allocation[0][i] = get_bits(&s->gb, 4);
|
|
}
|
|
|
|
/* scale factors */
|
|
for(i=0;i<bound;i++) {
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
if (allocation[ch][i])
|
|
scale_factors[ch][i] = get_bits(&s->gb, 6);
|
|
}
|
|
}
|
|
for(i=bound;i<SBLIMIT;i++) {
|
|
if (allocation[0][i]) {
|
|
scale_factors[0][i] = get_bits(&s->gb, 6);
|
|
scale_factors[1][i] = get_bits(&s->gb, 6);
|
|
}
|
|
}
|
|
|
|
/* compute samples */
|
|
for(j=0;j<12;j++) {
|
|
for(i=0;i<bound;i++) {
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
n = allocation[ch][i];
|
|
if (n) {
|
|
mant = get_bits(&s->gb, n + 1);
|
|
v = l1_unscale(n, mant, scale_factors[ch][i]);
|
|
} else {
|
|
v = 0;
|
|
}
|
|
s->sb_samples[ch][j][i] = v;
|
|
}
|
|
}
|
|
for(i=bound;i<SBLIMIT;i++) {
|
|
n = allocation[0][i];
|
|
if (n) {
|
|
mant = get_bits(&s->gb, n + 1);
|
|
v = l1_unscale(n, mant, scale_factors[0][i]);
|
|
s->sb_samples[0][j][i] = v;
|
|
v = l1_unscale(n, mant, scale_factors[1][i]);
|
|
s->sb_samples[1][j][i] = v;
|
|
} else {
|
|
s->sb_samples[0][j][i] = 0;
|
|
s->sb_samples[1][j][i] = 0;
|
|
}
|
|
}
|
|
}
|
|
return 12;
|
|
}
|
|
|
|
/* bitrate is in kb/s */
|
|
static int l2_select_table(int bitrate, int nb_channels, int freq, int lsf)
|
|
{
|
|
int ch_bitrate, table;
|
|
|
|
ch_bitrate = bitrate / nb_channels;
|
|
if (!lsf) {
|
|
if ((freq == 48000 && ch_bitrate >= 56) ||
|
|
(ch_bitrate >= 56 && ch_bitrate <= 80))
|
|
table = 0;
|
|
else if (freq != 48000 && ch_bitrate >= 96)
|
|
table = 1;
|
|
else if (freq != 32000 && ch_bitrate <= 48)
|
|
table = 2;
|
|
else
|
|
table = 3;
|
|
} else {
|
|
table = 4;
|
|
}
|
|
return table;
|
|
}
|
|
|
|
static int mp_decode_layer2(MPADecodeContext *s)
|
|
{
|
|
int sblimit; /* number of used subbands */
|
|
const unsigned char *alloc_table;
|
|
int table, bit_alloc_bits, i, j, ch, bound, v;
|
|
unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
|
|
unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
|
|
unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
|
|
int scale, qindex, bits, steps, k, l, m, b;
|
|
|
|
/* select decoding table */
|
|
table = l2_select_table(s->bit_rate / 1000, s->nb_channels,
|
|
s->sample_rate, s->lsf);
|
|
sblimit = sblimit_table[table];
|
|
alloc_table = alloc_tables[table];
|
|
|
|
if (s->mode == MPA_JSTEREO)
|
|
bound = (s->mode_ext + 1) * 4;
|
|
else
|
|
bound = sblimit;
|
|
|
|
#ifdef DEBUG
|
|
printf("bound=%d sblimit=%d\n", bound, sblimit);
|
|
#endif
|
|
/* parse bit allocation */
|
|
j = 0;
|
|
for(i=0;i<bound;i++) {
|
|
bit_alloc_bits = alloc_table[j];
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
|
|
}
|
|
j += 1 << bit_alloc_bits;
|
|
}
|
|
for(i=bound;i<sblimit;i++) {
|
|
bit_alloc_bits = alloc_table[j];
|
|
v = get_bits(&s->gb, bit_alloc_bits);
|
|
bit_alloc[0][i] = v;
|
|
bit_alloc[1][i] = v;
|
|
j += 1 << bit_alloc_bits;
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
{
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
for(i=0;i<sblimit;i++)
|
|
printf(" %d", bit_alloc[ch][i]);
|
|
printf("\n");
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* scale codes */
|
|
for(i=0;i<sblimit;i++) {
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
if (bit_alloc[ch][i])
|
|
scale_code[ch][i] = get_bits(&s->gb, 2);
|
|
}
|
|
}
|
|
|
|
/* scale factors */
|
|
for(i=0;i<sblimit;i++) {
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
if (bit_alloc[ch][i]) {
|
|
sf = scale_factors[ch][i];
|
|
switch(scale_code[ch][i]) {
|
|
default:
|
|
case 0:
|
|
sf[0] = get_bits(&s->gb, 6);
|
|
sf[1] = get_bits(&s->gb, 6);
|
|
sf[2] = get_bits(&s->gb, 6);
|
|
break;
|
|
case 2:
|
|
sf[0] = get_bits(&s->gb, 6);
|
|
sf[1] = sf[0];
|
|
sf[2] = sf[0];
|
|
break;
|
|
case 1:
|
|
sf[0] = get_bits(&s->gb, 6);
|
|
sf[2] = get_bits(&s->gb, 6);
|
|
sf[1] = sf[0];
|
|
break;
|
|
case 3:
|
|
sf[0] = get_bits(&s->gb, 6);
|
|
sf[2] = get_bits(&s->gb, 6);
|
|
sf[1] = sf[2];
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
for(i=0;i<sblimit;i++) {
|
|
if (bit_alloc[ch][i]) {
|
|
sf = scale_factors[ch][i];
|
|
printf(" %d %d %d", sf[0], sf[1], sf[2]);
|
|
} else {
|
|
printf(" -");
|
|
}
|
|
}
|
|
printf("\n");
|
|
}
|
|
#endif
|
|
|
|
/* samples */
|
|
for(k=0;k<3;k++) {
|
|
for(l=0;l<12;l+=3) {
|
|
j = 0;
|
|
for(i=0;i<bound;i++) {
|
|
bit_alloc_bits = alloc_table[j];
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
b = bit_alloc[ch][i];
|
|
if (b) {
|
|
scale = scale_factors[ch][i][k];
|
|
qindex = alloc_table[j+b];
|
|
bits = quant_bits[qindex];
|
|
if (bits < 0) {
|
|
/* 3 values at the same time */
|
|
v = get_bits(&s->gb, -bits);
|
|
steps = quant_steps[qindex];
|
|
s->sb_samples[ch][k * 12 + l + 0][i] =
|
|
l2_unscale_group(steps, v % steps, scale);
|
|
v = v / steps;
|
|
s->sb_samples[ch][k * 12 + l + 1][i] =
|
|
l2_unscale_group(steps, v % steps, scale);
|
|
v = v / steps;
|
|
s->sb_samples[ch][k * 12 + l + 2][i] =
|
|
l2_unscale_group(steps, v, scale);
|
|
} else {
|
|
for(m=0;m<3;m++) {
|
|
v = get_bits(&s->gb, bits);
|
|
v = l1_unscale(bits - 1, v, scale);
|
|
s->sb_samples[ch][k * 12 + l + m][i] = v;
|
|
}
|
|
}
|
|
} else {
|
|
s->sb_samples[ch][k * 12 + l + 0][i] = 0;
|
|
s->sb_samples[ch][k * 12 + l + 1][i] = 0;
|
|
s->sb_samples[ch][k * 12 + l + 2][i] = 0;
|
|
}
|
|
}
|
|
/* next subband in alloc table */
|
|
j += 1 << bit_alloc_bits;
|
|
}
|
|
/* XXX: find a way to avoid this duplication of code */
|
|
for(i=bound;i<sblimit;i++) {
|
|
bit_alloc_bits = alloc_table[j];
|
|
b = bit_alloc[0][i];
|
|
if (b) {
|
|
int mant, scale0, scale1;
|
|
scale0 = scale_factors[0][i][k];
|
|
scale1 = scale_factors[1][i][k];
|
|
qindex = alloc_table[j+b];
|
|
bits = quant_bits[qindex];
|
|
if (bits < 0) {
|
|
/* 3 values at the same time */
|
|
v = get_bits(&s->gb, -bits);
|
|
steps = quant_steps[qindex];
|
|
mant = v % steps;
|
|
v = v / steps;
|
|
s->sb_samples[0][k * 12 + l + 0][i] =
|
|
l2_unscale_group(steps, mant, scale0);
|
|
s->sb_samples[1][k * 12 + l + 0][i] =
|
|
l2_unscale_group(steps, mant, scale1);
|
|
mant = v % steps;
|
|
v = v / steps;
|
|
s->sb_samples[0][k * 12 + l + 1][i] =
|
|
l2_unscale_group(steps, mant, scale0);
|
|
s->sb_samples[1][k * 12 + l + 1][i] =
|
|
l2_unscale_group(steps, mant, scale1);
|
|
s->sb_samples[0][k * 12 + l + 2][i] =
|
|
l2_unscale_group(steps, v, scale0);
|
|
s->sb_samples[1][k * 12 + l + 2][i] =
|
|
l2_unscale_group(steps, v, scale1);
|
|
} else {
|
|
for(m=0;m<3;m++) {
|
|
mant = get_bits(&s->gb, bits);
|
|
s->sb_samples[0][k * 12 + l + m][i] =
|
|
l1_unscale(bits - 1, mant, scale0);
|
|
s->sb_samples[1][k * 12 + l + m][i] =
|
|
l1_unscale(bits - 1, mant, scale1);
|
|
}
|
|
}
|
|
} else {
|
|
s->sb_samples[0][k * 12 + l + 0][i] = 0;
|
|
s->sb_samples[0][k * 12 + l + 1][i] = 0;
|
|
s->sb_samples[0][k * 12 + l + 2][i] = 0;
|
|
s->sb_samples[1][k * 12 + l + 0][i] = 0;
|
|
s->sb_samples[1][k * 12 + l + 1][i] = 0;
|
|
s->sb_samples[1][k * 12 + l + 2][i] = 0;
|
|
}
|
|
/* next subband in alloc table */
|
|
j += 1 << bit_alloc_bits;
|
|
}
|
|
/* fill remaining samples to zero */
|
|
for(i=sblimit;i<SBLIMIT;i++) {
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
s->sb_samples[ch][k * 12 + l + 0][i] = 0;
|
|
s->sb_samples[ch][k * 12 + l + 1][i] = 0;
|
|
s->sb_samples[ch][k * 12 + l + 2][i] = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return 3 * 12;
|
|
}
|
|
|
|
/*
|
|
* Seek back in the stream for backstep bytes (at most 511 bytes)
|
|
*/
|
|
static void seek_to_maindata(MPADecodeContext *s, unsigned int backstep)
|
|
{
|
|
uint8_t *ptr;
|
|
|
|
/* compute current position in stream */
|
|
ptr = (uint8_t *)(s->gb.buffer + (get_bits_count(&s->gb)>>3));
|
|
|
|
/* copy old data before current one */
|
|
ptr -= backstep;
|
|
memcpy(ptr, s->inbuf1[s->inbuf_index ^ 1] +
|
|
BACKSTEP_SIZE + s->old_frame_size - backstep, backstep);
|
|
/* init get bits again */
|
|
init_get_bits(&s->gb, ptr, (s->frame_size + backstep)*8);
|
|
|
|
/* prepare next buffer */
|
|
s->inbuf_index ^= 1;
|
|
s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
|
|
s->old_frame_size = s->frame_size;
|
|
}
|
|
|
|
static void lsf_sf_expand(int *slen,
|
|
int sf, int n1, int n2, int n3)
|
|
{
|
|
if (n3) {
|
|
slen[3] = sf % n3;
|
|
sf /= n3;
|
|
} else {
|
|
slen[3] = 0;
|
|
}
|
|
if (n2) {
|
|
slen[2] = sf % n2;
|
|
sf /= n2;
|
|
} else {
|
|
slen[2] = 0;
|
|
}
|
|
slen[1] = sf % n1;
|
|
sf /= n1;
|
|
slen[0] = sf;
|
|
}
|
|
|
|
static void exponents_from_scale_factors(MPADecodeContext *s,
|
|
GranuleDef *g,
|
|
int16_t *exponents)
|
|
{
|
|
const uint8_t *bstab, *pretab;
|
|
int len, i, j, k, l, v0, shift, gain, gains[3];
|
|
int16_t *exp_ptr;
|
|
|
|
exp_ptr = exponents;
|
|
gain = g->global_gain - 210;
|
|
shift = g->scalefac_scale + 1;
|
|
|
|
bstab = band_size_long[s->sample_rate_index];
|
|
pretab = mpa_pretab[g->preflag];
|
|
for(i=0;i<g->long_end;i++) {
|
|
v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift);
|
|
len = bstab[i];
|
|
for(j=len;j>0;j--)
|
|
*exp_ptr++ = v0;
|
|
}
|
|
|
|
if (g->short_start < 13) {
|
|
bstab = band_size_short[s->sample_rate_index];
|
|
gains[0] = gain - (g->subblock_gain[0] << 3);
|
|
gains[1] = gain - (g->subblock_gain[1] << 3);
|
|
gains[2] = gain - (g->subblock_gain[2] << 3);
|
|
k = g->long_end;
|
|
for(i=g->short_start;i<13;i++) {
|
|
len = bstab[i];
|
|
for(l=0;l<3;l++) {
|
|
v0 = gains[l] - (g->scale_factors[k++] << shift);
|
|
for(j=len;j>0;j--)
|
|
*exp_ptr++ = v0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* handle n = 0 too */
|
|
static int get_bitsz(GetBitContext *s, int n)
|
|
{
|
|
if (n == 0)
|
|
return 0;
|
|
else
|
|
return get_bits(s, n);
|
|
}
|
|
|
|
static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
|
|
int16_t *exponents, int end_pos)
|
|
{
|
|
int s_index;
|
|
int linbits, code, x, y, l, v, i, j, k, pos;
|
|
GetBitContext last_gb;
|
|
VLC *vlc;
|
|
uint8_t *code_table;
|
|
|
|
/* low frequencies (called big values) */
|
|
s_index = 0;
|
|
for(i=0;i<3;i++) {
|
|
j = g->region_size[i];
|
|
if (j == 0)
|
|
continue;
|
|
/* select vlc table */
|
|
k = g->table_select[i];
|
|
l = mpa_huff_data[k][0];
|
|
linbits = mpa_huff_data[k][1];
|
|
vlc = &huff_vlc[l];
|
|
code_table = huff_code_table[l];
|
|
|
|
/* read huffcode and compute each couple */
|
|
for(;j>0;j--) {
|
|
if (get_bits_count(&s->gb) >= end_pos)
|
|
break;
|
|
if (code_table) {
|
|
code = get_vlc(&s->gb, vlc);
|
|
if (code < 0)
|
|
return -1;
|
|
y = code_table[code];
|
|
x = y >> 4;
|
|
y = y & 0x0f;
|
|
} else {
|
|
x = 0;
|
|
y = 0;
|
|
}
|
|
#ifdef DEBUG
|
|
printf("region=%d n=%d x=%d y=%d exp=%d\n",
|
|
i, g->region_size[i] - j, x, y, exponents[s_index]);
|
|
#endif
|
|
if (x) {
|
|
if (x == 15)
|
|
x += get_bitsz(&s->gb, linbits);
|
|
v = l3_unscale(x, exponents[s_index]);
|
|
if (get_bits(&s->gb, 1))
|
|
v = -v;
|
|
} else {
|
|
v = 0;
|
|
}
|
|
g->sb_hybrid[s_index++] = v;
|
|
if (y) {
|
|
if (y == 15)
|
|
y += get_bitsz(&s->gb, linbits);
|
|
v = l3_unscale(y, exponents[s_index]);
|
|
if (get_bits(&s->gb, 1))
|
|
v = -v;
|
|
} else {
|
|
v = 0;
|
|
}
|
|
g->sb_hybrid[s_index++] = v;
|
|
}
|
|
}
|
|
|
|
/* high frequencies */
|
|
vlc = &huff_quad_vlc[g->count1table_select];
|
|
last_gb.buffer = NULL;
|
|
while (s_index <= 572) {
|
|
pos = get_bits_count(&s->gb);
|
|
if (pos >= end_pos) {
|
|
if (pos > end_pos && last_gb.buffer != NULL) {
|
|
/* some encoders generate an incorrect size for this
|
|
part. We must go back into the data */
|
|
s_index -= 4;
|
|
s->gb = last_gb;
|
|
}
|
|
break;
|
|
}
|
|
last_gb= s->gb;
|
|
|
|
code = get_vlc(&s->gb, vlc);
|
|
#ifdef DEBUG
|
|
printf("t=%d code=%d\n", g->count1table_select, code);
|
|
#endif
|
|
if (code < 0)
|
|
return -1;
|
|
for(i=0;i<4;i++) {
|
|
if (code & (8 >> i)) {
|
|
/* non zero value. Could use a hand coded function for
|
|
'one' value */
|
|
v = l3_unscale(1, exponents[s_index]);
|
|
if(get_bits(&s->gb, 1))
|
|
v = -v;
|
|
} else {
|
|
v = 0;
|
|
}
|
|
g->sb_hybrid[s_index++] = v;
|
|
}
|
|
}
|
|
while (s_index < 576)
|
|
g->sb_hybrid[s_index++] = 0;
|
|
return 0;
|
|
}
|
|
|
|
/* Reorder short blocks from bitstream order to interleaved order. It
|
|
would be faster to do it in parsing, but the code would be far more
|
|
complicated */
|
|
static void reorder_block(MPADecodeContext *s, GranuleDef *g)
|
|
{
|
|
int i, j, k, len;
|
|
int32_t *ptr, *dst, *ptr1;
|
|
int32_t tmp[576];
|
|
|
|
if (g->block_type != 2)
|
|
return;
|
|
|
|
if (g->switch_point) {
|
|
if (s->sample_rate_index != 8) {
|
|
ptr = g->sb_hybrid + 36;
|
|
} else {
|
|
ptr = g->sb_hybrid + 48;
|
|
}
|
|
} else {
|
|
ptr = g->sb_hybrid;
|
|
}
|
|
|
|
for(i=g->short_start;i<13;i++) {
|
|
len = band_size_short[s->sample_rate_index][i];
|
|
ptr1 = ptr;
|
|
for(k=0;k<3;k++) {
|
|
dst = tmp + k;
|
|
for(j=len;j>0;j--) {
|
|
*dst = *ptr++;
|
|
dst += 3;
|
|
}
|
|
}
|
|
memcpy(ptr1, tmp, len * 3 * sizeof(int32_t));
|
|
}
|
|
}
|
|
|
|
#define ISQRT2 FIXR(0.70710678118654752440)
|
|
|
|
static void compute_stereo(MPADecodeContext *s,
|
|
GranuleDef *g0, GranuleDef *g1)
|
|
{
|
|
int i, j, k, l;
|
|
int32_t v1, v2;
|
|
int sf_max, tmp0, tmp1, sf, len, non_zero_found;
|
|
int32_t (*is_tab)[16];
|
|
int32_t *tab0, *tab1;
|
|
int non_zero_found_short[3];
|
|
|
|
/* intensity stereo */
|
|
if (s->mode_ext & MODE_EXT_I_STEREO) {
|
|
if (!s->lsf) {
|
|
is_tab = is_table;
|
|
sf_max = 7;
|
|
} else {
|
|
is_tab = is_table_lsf[g1->scalefac_compress & 1];
|
|
sf_max = 16;
|
|
}
|
|
|
|
tab0 = g0->sb_hybrid + 576;
|
|
tab1 = g1->sb_hybrid + 576;
|
|
|
|
non_zero_found_short[0] = 0;
|
|
non_zero_found_short[1] = 0;
|
|
non_zero_found_short[2] = 0;
|
|
k = (13 - g1->short_start) * 3 + g1->long_end - 3;
|
|
for(i = 12;i >= g1->short_start;i--) {
|
|
/* for last band, use previous scale factor */
|
|
if (i != 11)
|
|
k -= 3;
|
|
len = band_size_short[s->sample_rate_index][i];
|
|
for(l=2;l>=0;l--) {
|
|
tab0 -= len;
|
|
tab1 -= len;
|
|
if (!non_zero_found_short[l]) {
|
|
/* test if non zero band. if so, stop doing i-stereo */
|
|
for(j=0;j<len;j++) {
|
|
if (tab1[j] != 0) {
|
|
non_zero_found_short[l] = 1;
|
|
goto found1;
|
|
}
|
|
}
|
|
sf = g1->scale_factors[k + l];
|
|
if (sf >= sf_max)
|
|
goto found1;
|
|
|
|
v1 = is_tab[0][sf];
|
|
v2 = is_tab[1][sf];
|
|
for(j=0;j<len;j++) {
|
|
tmp0 = tab0[j];
|
|
tab0[j] = MULL(tmp0, v1);
|
|
tab1[j] = MULL(tmp0, v2);
|
|
}
|
|
} else {
|
|
found1:
|
|
if (s->mode_ext & MODE_EXT_MS_STEREO) {
|
|
/* lower part of the spectrum : do ms stereo
|
|
if enabled */
|
|
for(j=0;j<len;j++) {
|
|
tmp0 = tab0[j];
|
|
tmp1 = tab1[j];
|
|
tab0[j] = MULL(tmp0 + tmp1, ISQRT2);
|
|
tab1[j] = MULL(tmp0 - tmp1, ISQRT2);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
non_zero_found = non_zero_found_short[0] |
|
|
non_zero_found_short[1] |
|
|
non_zero_found_short[2];
|
|
|
|
for(i = g1->long_end - 1;i >= 0;i--) {
|
|
len = band_size_long[s->sample_rate_index][i];
|
|
tab0 -= len;
|
|
tab1 -= len;
|
|
/* test if non zero band. if so, stop doing i-stereo */
|
|
if (!non_zero_found) {
|
|
for(j=0;j<len;j++) {
|
|
if (tab1[j] != 0) {
|
|
non_zero_found = 1;
|
|
goto found2;
|
|
}
|
|
}
|
|
/* for last band, use previous scale factor */
|
|
k = (i == 21) ? 20 : i;
|
|
sf = g1->scale_factors[k];
|
|
if (sf >= sf_max)
|
|
goto found2;
|
|
v1 = is_tab[0][sf];
|
|
v2 = is_tab[1][sf];
|
|
for(j=0;j<len;j++) {
|
|
tmp0 = tab0[j];
|
|
tab0[j] = MULL(tmp0, v1);
|
|
tab1[j] = MULL(tmp0, v2);
|
|
}
|
|
} else {
|
|
found2:
|
|
if (s->mode_ext & MODE_EXT_MS_STEREO) {
|
|
/* lower part of the spectrum : do ms stereo
|
|
if enabled */
|
|
for(j=0;j<len;j++) {
|
|
tmp0 = tab0[j];
|
|
tmp1 = tab1[j];
|
|
tab0[j] = MULL(tmp0 + tmp1, ISQRT2);
|
|
tab1[j] = MULL(tmp0 - tmp1, ISQRT2);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} else if (s->mode_ext & MODE_EXT_MS_STEREO) {
|
|
/* ms stereo ONLY */
|
|
/* NOTE: the 1/sqrt(2) normalization factor is included in the
|
|
global gain */
|
|
tab0 = g0->sb_hybrid;
|
|
tab1 = g1->sb_hybrid;
|
|
for(i=0;i<576;i++) {
|
|
tmp0 = tab0[i];
|
|
tmp1 = tab1[i];
|
|
tab0[i] = tmp0 + tmp1;
|
|
tab1[i] = tmp0 - tmp1;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void compute_antialias(MPADecodeContext *s,
|
|
GranuleDef *g)
|
|
{
|
|
int32_t *ptr, *p0, *p1, *csa;
|
|
int n, tmp0, tmp1, i, j;
|
|
|
|
/* we antialias only "long" bands */
|
|
if (g->block_type == 2) {
|
|
if (!g->switch_point)
|
|
return;
|
|
/* XXX: check this for 8000Hz case */
|
|
n = 1;
|
|
} else {
|
|
n = SBLIMIT - 1;
|
|
}
|
|
|
|
ptr = g->sb_hybrid + 18;
|
|
for(i = n;i > 0;i--) {
|
|
p0 = ptr - 1;
|
|
p1 = ptr;
|
|
csa = &csa_table[0][0];
|
|
for(j=0;j<8;j++) {
|
|
tmp0 = *p0;
|
|
tmp1 = *p1;
|
|
*p0 = FRAC_RND(MUL64(tmp0, csa[0]) - MUL64(tmp1, csa[1]));
|
|
*p1 = FRAC_RND(MUL64(tmp0, csa[1]) + MUL64(tmp1, csa[0]));
|
|
p0--;
|
|
p1++;
|
|
csa += 2;
|
|
}
|
|
ptr += 18;
|
|
}
|
|
}
|
|
|
|
static void compute_imdct(MPADecodeContext *s,
|
|
GranuleDef *g,
|
|
int32_t *sb_samples,
|
|
int32_t *mdct_buf)
|
|
{
|
|
int32_t *ptr, *win, *win1, *buf, *buf2, *out_ptr, *ptr1;
|
|
int32_t in[6];
|
|
int32_t out[36];
|
|
int32_t out2[12];
|
|
int i, j, k, mdct_long_end, v, sblimit;
|
|
|
|
/* find last non zero block */
|
|
ptr = g->sb_hybrid + 576;
|
|
ptr1 = g->sb_hybrid + 2 * 18;
|
|
while (ptr >= ptr1) {
|
|
ptr -= 6;
|
|
v = ptr[0] | ptr[1] | ptr[2] | ptr[3] | ptr[4] | ptr[5];
|
|
if (v != 0)
|
|
break;
|
|
}
|
|
sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
|
|
|
|
if (g->block_type == 2) {
|
|
/* XXX: check for 8000 Hz */
|
|
if (g->switch_point)
|
|
mdct_long_end = 2;
|
|
else
|
|
mdct_long_end = 0;
|
|
} else {
|
|
mdct_long_end = sblimit;
|
|
}
|
|
|
|
buf = mdct_buf;
|
|
ptr = g->sb_hybrid;
|
|
for(j=0;j<mdct_long_end;j++) {
|
|
imdct36(out, ptr);
|
|
/* apply window & overlap with previous buffer */
|
|
out_ptr = sb_samples + j;
|
|
/* select window */
|
|
if (g->switch_point && j < 2)
|
|
win1 = mdct_win[0];
|
|
else
|
|
win1 = mdct_win[g->block_type];
|
|
/* select frequency inversion */
|
|
win = win1 + ((4 * 36) & -(j & 1));
|
|
for(i=0;i<18;i++) {
|
|
*out_ptr = MULL(out[i], win[i]) + buf[i];
|
|
buf[i] = MULL(out[i + 18], win[i + 18]);
|
|
out_ptr += SBLIMIT;
|
|
}
|
|
ptr += 18;
|
|
buf += 18;
|
|
}
|
|
for(j=mdct_long_end;j<sblimit;j++) {
|
|
for(i=0;i<6;i++) {
|
|
out[i] = 0;
|
|
out[6 + i] = 0;
|
|
out[30+i] = 0;
|
|
}
|
|
/* select frequency inversion */
|
|
win = mdct_win[2] + ((4 * 36) & -(j & 1));
|
|
buf2 = out + 6;
|
|
for(k=0;k<3;k++) {
|
|
/* reorder input for short mdct */
|
|
ptr1 = ptr + k;
|
|
for(i=0;i<6;i++) {
|
|
in[i] = *ptr1;
|
|
ptr1 += 3;
|
|
}
|
|
imdct12(out2, in);
|
|
/* apply 12 point window and do small overlap */
|
|
for(i=0;i<6;i++) {
|
|
buf2[i] = MULL(out2[i], win[i]) + buf2[i];
|
|
buf2[i + 6] = MULL(out2[i + 6], win[i + 6]);
|
|
}
|
|
buf2 += 6;
|
|
}
|
|
/* overlap */
|
|
out_ptr = sb_samples + j;
|
|
for(i=0;i<18;i++) {
|
|
*out_ptr = out[i] + buf[i];
|
|
buf[i] = out[i + 18];
|
|
out_ptr += SBLIMIT;
|
|
}
|
|
ptr += 18;
|
|
buf += 18;
|
|
}
|
|
/* zero bands */
|
|
for(j=sblimit;j<SBLIMIT;j++) {
|
|
/* overlap */
|
|
out_ptr = sb_samples + j;
|
|
for(i=0;i<18;i++) {
|
|
*out_ptr = buf[i];
|
|
buf[i] = 0;
|
|
out_ptr += SBLIMIT;
|
|
}
|
|
buf += 18;
|
|
}
|
|
}
|
|
|
|
/* main layer3 decoding function */
|
|
static int mp_decode_layer3(MPADecodeContext *s)
|
|
{
|
|
int nb_granules, main_data_begin, private_bits;
|
|
int gr, ch, blocksplit_flag, i, j, k, n, bits_pos, bits_left;
|
|
GranuleDef granules[2][2], *g;
|
|
int16_t exponents[576];
|
|
|
|
/* read side info */
|
|
if (s->lsf) {
|
|
main_data_begin = get_bits(&s->gb, 8);
|
|
if (s->nb_channels == 2)
|
|
private_bits = get_bits(&s->gb, 2);
|
|
else
|
|
private_bits = get_bits(&s->gb, 1);
|
|
nb_granules = 1;
|
|
} else {
|
|
main_data_begin = get_bits(&s->gb, 9);
|
|
if (s->nb_channels == 2)
|
|
private_bits = get_bits(&s->gb, 3);
|
|
else
|
|
private_bits = get_bits(&s->gb, 5);
|
|
nb_granules = 2;
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
granules[ch][0].scfsi = 0; /* all scale factors are transmitted */
|
|
granules[ch][1].scfsi = get_bits(&s->gb, 4);
|
|
}
|
|
}
|
|
|
|
for(gr=0;gr<nb_granules;gr++) {
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
#ifdef DEBUG
|
|
printf("gr=%d ch=%d: side_info\n", gr, ch);
|
|
#endif
|
|
g = &granules[ch][gr];
|
|
g->part2_3_length = get_bits(&s->gb, 12);
|
|
g->big_values = get_bits(&s->gb, 9);
|
|
g->global_gain = get_bits(&s->gb, 8);
|
|
/* if MS stereo only is selected, we precompute the
|
|
1/sqrt(2) renormalization factor */
|
|
if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==
|
|
MODE_EXT_MS_STEREO)
|
|
g->global_gain -= 2;
|
|
if (s->lsf)
|
|
g->scalefac_compress = get_bits(&s->gb, 9);
|
|
else
|
|
g->scalefac_compress = get_bits(&s->gb, 4);
|
|
blocksplit_flag = get_bits(&s->gb, 1);
|
|
if (blocksplit_flag) {
|
|
g->block_type = get_bits(&s->gb, 2);
|
|
if (g->block_type == 0)
|
|
return -1;
|
|
g->switch_point = get_bits(&s->gb, 1);
|
|
for(i=0;i<2;i++)
|
|
g->table_select[i] = get_bits(&s->gb, 5);
|
|
for(i=0;i<3;i++)
|
|
g->subblock_gain[i] = get_bits(&s->gb, 3);
|
|
/* compute huffman coded region sizes */
|
|
if (g->block_type == 2)
|
|
g->region_size[0] = (36 / 2);
|
|
else {
|
|
if (s->sample_rate_index <= 2)
|
|
g->region_size[0] = (36 / 2);
|
|
else if (s->sample_rate_index != 8)
|
|
g->region_size[0] = (54 / 2);
|
|
else
|
|
g->region_size[0] = (108 / 2);
|
|
}
|
|
g->region_size[1] = (576 / 2);
|
|
} else {
|
|
int region_address1, region_address2, l;
|
|
g->block_type = 0;
|
|
g->switch_point = 0;
|
|
for(i=0;i<3;i++)
|
|
g->table_select[i] = get_bits(&s->gb, 5);
|
|
/* compute huffman coded region sizes */
|
|
region_address1 = get_bits(&s->gb, 4);
|
|
region_address2 = get_bits(&s->gb, 3);
|
|
#ifdef DEBUG
|
|
printf("region1=%d region2=%d\n",
|
|
region_address1, region_address2);
|
|
#endif
|
|
g->region_size[0] =
|
|
band_index_long[s->sample_rate_index][region_address1 + 1] >> 1;
|
|
l = region_address1 + region_address2 + 2;
|
|
/* should not overflow */
|
|
if (l > 22)
|
|
l = 22;
|
|
g->region_size[1] =
|
|
band_index_long[s->sample_rate_index][l] >> 1;
|
|
}
|
|
/* convert region offsets to region sizes and truncate
|
|
size to big_values */
|
|
g->region_size[2] = (576 / 2);
|
|
j = 0;
|
|
for(i=0;i<3;i++) {
|
|
k = g->region_size[i];
|
|
if (k > g->big_values)
|
|
k = g->big_values;
|
|
g->region_size[i] = k - j;
|
|
j = k;
|
|
}
|
|
|
|
/* compute band indexes */
|
|
if (g->block_type == 2) {
|
|
if (g->switch_point) {
|
|
/* if switched mode, we handle the 36 first samples as
|
|
long blocks. For 8000Hz, we handle the 48 first
|
|
exponents as long blocks (XXX: check this!) */
|
|
if (s->sample_rate_index <= 2)
|
|
g->long_end = 8;
|
|
else if (s->sample_rate_index != 8)
|
|
g->long_end = 6;
|
|
else
|
|
g->long_end = 4; /* 8000 Hz */
|
|
|
|
if (s->sample_rate_index != 8)
|
|
g->short_start = 3;
|
|
else
|
|
g->short_start = 2;
|
|
} else {
|
|
g->long_end = 0;
|
|
g->short_start = 0;
|
|
}
|
|
} else {
|
|
g->short_start = 13;
|
|
g->long_end = 22;
|
|
}
|
|
|
|
g->preflag = 0;
|
|
if (!s->lsf)
|
|
g->preflag = get_bits(&s->gb, 1);
|
|
g->scalefac_scale = get_bits(&s->gb, 1);
|
|
g->count1table_select = get_bits(&s->gb, 1);
|
|
#ifdef DEBUG
|
|
printf("block_type=%d switch_point=%d\n",
|
|
g->block_type, g->switch_point);
|
|
#endif
|
|
}
|
|
}
|
|
|
|
/* now we get bits from the main_data_begin offset */
|
|
#ifdef DEBUG
|
|
printf("seekback: %d\n", main_data_begin);
|
|
#endif
|
|
seek_to_maindata(s, main_data_begin);
|
|
|
|
for(gr=0;gr<nb_granules;gr++) {
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
g = &granules[ch][gr];
|
|
|
|
bits_pos = get_bits_count(&s->gb);
|
|
|
|
if (!s->lsf) {
|
|
uint8_t *sc;
|
|
int slen, slen1, slen2;
|
|
|
|
/* MPEG1 scale factors */
|
|
slen1 = slen_table[0][g->scalefac_compress];
|
|
slen2 = slen_table[1][g->scalefac_compress];
|
|
#ifdef DEBUG
|
|
printf("slen1=%d slen2=%d\n", slen1, slen2);
|
|
#endif
|
|
if (g->block_type == 2) {
|
|
n = g->switch_point ? 17 : 18;
|
|
j = 0;
|
|
for(i=0;i<n;i++)
|
|
g->scale_factors[j++] = get_bitsz(&s->gb, slen1);
|
|
for(i=0;i<18;i++)
|
|
g->scale_factors[j++] = get_bitsz(&s->gb, slen2);
|
|
for(i=0;i<3;i++)
|
|
g->scale_factors[j++] = 0;
|
|
} else {
|
|
sc = granules[ch][0].scale_factors;
|
|
j = 0;
|
|
for(k=0;k<4;k++) {
|
|
n = (k == 0 ? 6 : 5);
|
|
if ((g->scfsi & (0x8 >> k)) == 0) {
|
|
slen = (k < 2) ? slen1 : slen2;
|
|
for(i=0;i<n;i++)
|
|
g->scale_factors[j++] = get_bitsz(&s->gb, slen);
|
|
} else {
|
|
/* simply copy from last granule */
|
|
for(i=0;i<n;i++) {
|
|
g->scale_factors[j] = sc[j];
|
|
j++;
|
|
}
|
|
}
|
|
}
|
|
g->scale_factors[j++] = 0;
|
|
}
|
|
#if defined(DEBUG)
|
|
{
|
|
printf("scfsi=%x gr=%d ch=%d scale_factors:\n",
|
|
g->scfsi, gr, ch);
|
|
for(i=0;i<j;i++)
|
|
printf(" %d", g->scale_factors[i]);
|
|
printf("\n");
|
|
}
|
|
#endif
|
|
} else {
|
|
int tindex, tindex2, slen[4], sl, sf;
|
|
|
|
/* LSF scale factors */
|
|
if (g->block_type == 2) {
|
|
tindex = g->switch_point ? 2 : 1;
|
|
} else {
|
|
tindex = 0;
|
|
}
|
|
sf = g->scalefac_compress;
|
|
if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
|
|
/* intensity stereo case */
|
|
sf >>= 1;
|
|
if (sf < 180) {
|
|
lsf_sf_expand(slen, sf, 6, 6, 0);
|
|
tindex2 = 3;
|
|
} else if (sf < 244) {
|
|
lsf_sf_expand(slen, sf - 180, 4, 4, 0);
|
|
tindex2 = 4;
|
|
} else {
|
|
lsf_sf_expand(slen, sf - 244, 3, 0, 0);
|
|
tindex2 = 5;
|
|
}
|
|
} else {
|
|
/* normal case */
|
|
if (sf < 400) {
|
|
lsf_sf_expand(slen, sf, 5, 4, 4);
|
|
tindex2 = 0;
|
|
} else if (sf < 500) {
|
|
lsf_sf_expand(slen, sf - 400, 5, 4, 0);
|
|
tindex2 = 1;
|
|
} else {
|
|
lsf_sf_expand(slen, sf - 500, 3, 0, 0);
|
|
tindex2 = 2;
|
|
g->preflag = 1;
|
|
}
|
|
}
|
|
|
|
j = 0;
|
|
for(k=0;k<4;k++) {
|
|
n = lsf_nsf_table[tindex2][tindex][k];
|
|
sl = slen[k];
|
|
for(i=0;i<n;i++)
|
|
g->scale_factors[j++] = get_bitsz(&s->gb, sl);
|
|
}
|
|
/* XXX: should compute exact size */
|
|
for(;j<40;j++)
|
|
g->scale_factors[j] = 0;
|
|
#if defined(DEBUG)
|
|
{
|
|
printf("gr=%d ch=%d scale_factors:\n",
|
|
gr, ch);
|
|
for(i=0;i<40;i++)
|
|
printf(" %d", g->scale_factors[i]);
|
|
printf("\n");
|
|
}
|
|
#endif
|
|
}
|
|
|
|
exponents_from_scale_factors(s, g, exponents);
|
|
|
|
/* read Huffman coded residue */
|
|
if (huffman_decode(s, g, exponents,
|
|
bits_pos + g->part2_3_length) < 0)
|
|
return -1;
|
|
|
|
/* skip extension bits */
|
|
bits_left = g->part2_3_length - (get_bits_count(&s->gb) - bits_pos);
|
|
if (bits_left < 0) {
|
|
#ifdef DEBUG
|
|
printf("bits_left=%d\n", bits_left);
|
|
#endif
|
|
return -1;
|
|
}
|
|
while (bits_left >= 16) {
|
|
skip_bits(&s->gb, 16);
|
|
bits_left -= 16;
|
|
}
|
|
if (bits_left > 0)
|
|
skip_bits(&s->gb, bits_left);
|
|
} /* ch */
|
|
|
|
if (s->nb_channels == 2)
|
|
compute_stereo(s, &granules[0][gr], &granules[1][gr]);
|
|
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
g = &granules[ch][gr];
|
|
|
|
reorder_block(s, g);
|
|
compute_antialias(s, g);
|
|
compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
|
|
}
|
|
} /* gr */
|
|
return nb_granules * 18;
|
|
}
|
|
|
|
static int mp_decode_frame(MPADecodeContext *s,
|
|
int16_t *samples)
|
|
{
|
|
int i, nb_frames, ch;
|
|
int16_t *samples_ptr;
|
|
|
|
init_get_bits(&s->gb, s->inbuf + HEADER_SIZE,
|
|
(s->inbuf_ptr - s->inbuf - HEADER_SIZE)*8);
|
|
|
|
/* skip error protection field */
|
|
if (s->error_protection)
|
|
get_bits(&s->gb, 16);
|
|
|
|
#ifdef DEBUG
|
|
printf("frame %d:\n", s->frame_count);
|
|
#endif
|
|
switch(s->layer) {
|
|
case 1:
|
|
nb_frames = mp_decode_layer1(s);
|
|
break;
|
|
case 2:
|
|
nb_frames = mp_decode_layer2(s);
|
|
break;
|
|
case 3:
|
|
default:
|
|
nb_frames = mp_decode_layer3(s);
|
|
break;
|
|
}
|
|
#if defined(DEBUG)
|
|
for(i=0;i<nb_frames;i++) {
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
int j;
|
|
printf("%d-%d:", i, ch);
|
|
for(j=0;j<SBLIMIT;j++)
|
|
printf(" %0.6f", (double)s->sb_samples[ch][i][j] / FRAC_ONE);
|
|
printf("\n");
|
|
}
|
|
}
|
|
#endif
|
|
/* apply the synthesis filter */
|
|
for(ch=0;ch<s->nb_channels;ch++) {
|
|
samples_ptr = samples + ch;
|
|
for(i=0;i<nb_frames;i++) {
|
|
synth_filter(s, ch, samples_ptr, s->nb_channels,
|
|
s->sb_samples[ch][i]);
|
|
samples_ptr += 32 * s->nb_channels;
|
|
}
|
|
}
|
|
#ifdef DEBUG
|
|
s->frame_count++;
|
|
#endif
|
|
return nb_frames * 32 * sizeof(short) * s->nb_channels;
|
|
}
|
|
|
|
int mpaudec_decode_frame(MPAuDecContext * mpctx,
|
|
void *data, int *data_size,
|
|
const uint8_t * buf, int buf_size)
|
|
{
|
|
MPADecodeContext *s;
|
|
const uint8_t *buf_ptr = buf;
|
|
int out_size = 0;
|
|
int16_t *out_samples = data;
|
|
assert(mpctx != NULL);
|
|
assert(mpctx->priv_data != NULL);
|
|
s = mpctx->priv_data;
|
|
|
|
while (buf_size > 0 && out_size == 0) {
|
|
uint32_t header;
|
|
uint32_t free_format_next_header = 0;
|
|
int len = s->inbuf_ptr - s->inbuf;
|
|
if (s->frame_size == 0) {
|
|
/* no header seen : find one. We need at least HEADER_SIZE
|
|
bytes to parse it */
|
|
len = HEADER_SIZE - len;
|
|
if (len > buf_size)
|
|
len = buf_size;
|
|
if (len > 0) {
|
|
memcpy(s->inbuf_ptr, buf_ptr, len);
|
|
buf_ptr += len;
|
|
buf_size -= len;
|
|
s->inbuf_ptr += len;
|
|
}
|
|
if ((s->inbuf_ptr - s->inbuf) >= HEADER_SIZE) {
|
|
header = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
|
|
(s->inbuf[2] << 8) | s->inbuf[3];
|
|
|
|
if (check_header(header) < 0) {
|
|
/* no sync found : move by one byte (inefficient, but simple!) */
|
|
memmove(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
|
|
s->inbuf_ptr--;
|
|
#ifdef DEBUG
|
|
printf("skip %x\n", header);
|
|
#endif
|
|
/* reset free format frame size to give a chance
|
|
to get a new bitrate */
|
|
s->free_format_frame_size = 0;
|
|
} else {
|
|
if (decode_header(s, header) == 1) {
|
|
/* free format: prepare to compute frame size */
|
|
s->frame_size = -1;
|
|
}
|
|
/* update codec info */
|
|
mpctx->sample_rate = s->sample_rate;
|
|
mpctx->channels = s->nb_channels;
|
|
mpctx->bit_rate = s->bit_rate;
|
|
mpctx->layer = s->layer;
|
|
switch(s->layer) {
|
|
case 1:
|
|
mpctx->frame_size = 384;
|
|
break;
|
|
case 2:
|
|
mpctx->frame_size = 1152;
|
|
break;
|
|
case 3:
|
|
if (s->lsf)
|
|
mpctx->frame_size = 576;
|
|
else
|
|
mpctx->frame_size = 1152;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
} else if (s->frame_size == -1) {
|
|
/* free format : find next sync to compute frame size */
|
|
len = MPA_MAX_CODED_FRAME_SIZE - len;
|
|
if (len > buf_size)
|
|
len = buf_size;
|
|
if (len == 0) {
|
|
/* frame too long: resync */
|
|
s->frame_size = 0;
|
|
memmove(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
|
|
s->inbuf_ptr--;
|
|
} else {
|
|
uint8_t *p, *pend;
|
|
uint32_t header1;
|
|
int padding;
|
|
|
|
memcpy(s->inbuf_ptr, buf_ptr, len);
|
|
/* check for header */
|
|
p = s->inbuf_ptr - 3;
|
|
pend = s->inbuf_ptr + len - 4;
|
|
while (p <= pend && free_format_next_header == 0) {
|
|
header = (p[0] << 24) | (p[1] << 16) |
|
|
(p[2] << 8) | p[3];
|
|
header1 = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
|
|
(s->inbuf[2] << 8) | s->inbuf[3];
|
|
/* check with high probability that we have a
|
|
valid header */
|
|
if ((header & SAME_HEADER_MASK) ==
|
|
(header1 & SAME_HEADER_MASK)) {
|
|
/* header found: update pointers */
|
|
len = (p + 4) - s->inbuf_ptr;
|
|
buf_ptr += len;
|
|
buf_size -= len;
|
|
s->inbuf_ptr = p;
|
|
free_format_next_header = header;
|
|
/* compute frame size */
|
|
s->free_format_frame_size = s->inbuf_ptr - s->inbuf;
|
|
padding = (header1 >> 9) & 1;
|
|
if (s->layer == 1)
|
|
s->free_format_frame_size -= padding * 4;
|
|
else
|
|
s->free_format_frame_size -= padding;
|
|
#ifdef DEBUG
|
|
printf("free frame size=%d padding=%d\n",
|
|
s->free_format_frame_size, padding);
|
|
#endif
|
|
decode_header(s, header1);
|
|
} else
|
|
p++;
|
|
}
|
|
if (free_format_next_header == 0) {
|
|
/* not found: simply increase pointers */
|
|
buf_ptr += len;
|
|
s->inbuf_ptr += len;
|
|
buf_size -= len;
|
|
}
|
|
}
|
|
} else if (len < s->frame_size) {
|
|
if (s->frame_size > MPA_MAX_CODED_FRAME_SIZE)
|
|
s->frame_size = MPA_MAX_CODED_FRAME_SIZE;
|
|
len = s->frame_size - len;
|
|
if (len > buf_size)
|
|
len = buf_size;
|
|
memcpy(s->inbuf_ptr, buf_ptr, len);
|
|
buf_ptr += len;
|
|
s->inbuf_ptr += len;
|
|
buf_size -= len;
|
|
}
|
|
if (s->frame_size > 0 &&
|
|
(s->inbuf_ptr - s->inbuf) >= s->frame_size) {
|
|
mpctx->coded_frame_size = s->frame_size;
|
|
if (mpctx->parse_only) {
|
|
/* simply return the frame data */
|
|
*(uint8_t **)data = s->inbuf;
|
|
out_size = s->inbuf_ptr - s->inbuf;
|
|
} else {
|
|
out_size = mp_decode_frame(s, out_samples);
|
|
}
|
|
if (free_format_next_header != 0) {
|
|
s->inbuf[0] = free_format_next_header >> 24;
|
|
s->inbuf[1] = free_format_next_header >> 16;
|
|
s->inbuf[2] = free_format_next_header >> 8;
|
|
s->inbuf[3] = free_format_next_header;
|
|
s->inbuf_ptr = s->inbuf + 4;
|
|
} else
|
|
s->inbuf_ptr = s->inbuf;
|
|
s->frame_size = 0;
|
|
}
|
|
}
|
|
*data_size = out_size;
|
|
return buf_ptr - buf;
|
|
}
|
|
|
|
void mpaudec_clear(MPAuDecContext *mpctx)
|
|
{
|
|
assert(mpctx != NULL);
|
|
free(mpctx->priv_data);
|
|
memset(mpctx, 0, sizeof(MPAuDecContext));
|
|
}
|