2010 lines
64 KiB
C
2010 lines
64 KiB
C
/*
|
|
* AC-3 Audio Decoder
|
|
* This code is developed as part of Google Summer of Code 2006 Program.
|
|
*
|
|
* Copyright (c) 2006 Kartikey Mahendra BHATT (bhattkm at gmail dot com).
|
|
*
|
|
* For exponent decoding the code is inspired by the code in liba52 by
|
|
* Michel Lespinasse and Aaron Holtzman.
|
|
* http://liba52.sourceforge.net
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stddef.h>
|
|
#include <math.h>
|
|
#include <string.h>
|
|
|
|
#define ALT_BITSTREAM_READER
|
|
|
|
#include "avcodec.h"
|
|
#include "ac3.h"
|
|
#include "ac3tab.h"
|
|
#include "bitstream.h"
|
|
#include "dsputil.h"
|
|
#include "random.h"
|
|
|
|
static uint8_t bndtab[51];
|
|
static uint8_t masktab[253];
|
|
|
|
static const int nfchans_tbl[8] = { 2, 1, 2, 3, 3, 4, 4, 5 };
|
|
|
|
/* table for exponent to scale_factor mapping
|
|
* scale_factor[i] = 2 ^ -(i + 15)
|
|
*/
|
|
static float scale_factors[25];
|
|
|
|
static int16_t psdtab[25];
|
|
|
|
static int8_t exp_1[128];
|
|
static int8_t exp_2[128];
|
|
static int8_t exp_3[128];
|
|
|
|
static int16_t l3_quantizers_1[32];
|
|
static int16_t l3_quantizers_2[32];
|
|
static int16_t l3_quantizers_3[32];
|
|
|
|
static int16_t l5_quantizers_1[128];
|
|
static int16_t l5_quantizers_2[128];
|
|
static int16_t l5_quantizers_3[128];
|
|
|
|
static int16_t l7_quantizers[7];
|
|
|
|
static int16_t l11_quantizers_1[128];
|
|
static int16_t l11_quantizers_2[128];
|
|
|
|
static int16_t l15_quantizers[15];
|
|
|
|
static const uint8_t qntztab[16] = { 0, 5, 7, 3, 7, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16 };
|
|
|
|
/* Adjustmens in dB gain */
|
|
#define LEVEL_MINUS_3DB 0.7071067811865476
|
|
#define LEVEL_MINUS_4POINT5DB 0.5946035575013605
|
|
#define LEVEL_MINUS_6DB 0.5000000000000000
|
|
#define LEVEL_PLUS_3DB 1.4142135623730951
|
|
#define LEVEL_PLUS_6DB 2.0000000000000000
|
|
#define LEVEL_ZERO 0.0000000000000000
|
|
|
|
static const float clevs[4] = { LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB,
|
|
LEVEL_MINUS_6DB, LEVEL_MINUS_4POINT5DB };
|
|
|
|
static const float slevs[4] = { LEVEL_MINUS_3DB, LEVEL_MINUS_6DB, LEVEL_ZERO, LEVEL_MINUS_6DB };
|
|
|
|
#define N 512 /* constant for IMDCT Block size */
|
|
|
|
#define BLOCK_SIZE 256
|
|
|
|
/* Output and input configurations. */
|
|
#define AC3_OUTPUT_UNMODIFIED 0x01
|
|
#define AC3_OUTPUT_MONO 0x02
|
|
#define AC3_OUTPUT_STEREO 0x04
|
|
#define AC3_OUTPUT_DOLBY 0x08
|
|
#define AC3_OUTPUT_LFEON 0x10
|
|
|
|
typedef struct {
|
|
uint16_t crc1;
|
|
uint8_t fscod;
|
|
|
|
uint8_t acmod;
|
|
uint8_t cmixlev;
|
|
uint8_t surmixlev;
|
|
uint8_t dsurmod;
|
|
|
|
uint8_t blksw;
|
|
uint8_t dithflag;
|
|
uint8_t cplinu;
|
|
uint8_t chincpl;
|
|
uint8_t phsflginu;
|
|
uint8_t cplbegf;
|
|
uint8_t cplendf;
|
|
uint8_t cplcoe;
|
|
uint32_t cplbndstrc;
|
|
uint8_t rematstr;
|
|
uint8_t rematflg;
|
|
uint8_t cplexpstr;
|
|
uint8_t lfeexpstr;
|
|
uint8_t chexpstr[5];
|
|
uint8_t sdcycod;
|
|
uint8_t fdcycod;
|
|
uint8_t sgaincod;
|
|
uint8_t dbpbcod;
|
|
uint8_t floorcod;
|
|
uint8_t csnroffst;
|
|
uint8_t cplfsnroffst;
|
|
uint8_t cplfgaincod;
|
|
uint8_t fsnroffst[5];
|
|
uint8_t fgaincod[5];
|
|
uint8_t lfefsnroffst;
|
|
uint8_t lfefgaincod;
|
|
uint8_t cplfleak;
|
|
uint8_t cplsleak;
|
|
uint8_t cpldeltbae;
|
|
uint8_t deltbae[5];
|
|
uint8_t cpldeltnseg;
|
|
uint8_t cpldeltoffst[8];
|
|
uint8_t cpldeltlen[8];
|
|
uint8_t cpldeltba[8];
|
|
uint8_t deltnseg[5];
|
|
uint8_t deltoffst[5][8];
|
|
uint8_t deltlen[5][8];
|
|
uint8_t deltba[5][8];
|
|
|
|
/* Derived Attributes. */
|
|
int sampling_rate;
|
|
int bit_rate;
|
|
int frame_size;
|
|
|
|
int nfchans; //number of channels
|
|
int lfeon; //lfe channel in use
|
|
|
|
float dynrng; //dynamic range gain
|
|
float dynrng2; //dynamic range gain for 1+1 mode
|
|
float chcoeffs[6]; //normalized channel coefficients
|
|
float cplco[5][18]; //coupling coordinates
|
|
int ncplbnd; //number of coupling bands
|
|
int ncplsubnd; //number of coupling sub bands
|
|
int cplstrtmant; //coupling start mantissa
|
|
int cplendmant; //coupling end mantissa
|
|
int endmant[5]; //channel end mantissas
|
|
|
|
uint8_t dcplexps[256]; //decoded coupling exponents
|
|
uint8_t dexps[5][256]; //decoded fbw channel exponents
|
|
uint8_t dlfeexps[256]; //decoded lfe channel exponents
|
|
uint8_t cplbap[256]; //coupling bit allocation pointers
|
|
uint8_t bap[5][256]; //fbw channel bit allocation pointers
|
|
uint8_t lfebap[256]; //lfe channel bit allocation pointers
|
|
|
|
int blkoutput; //output configuration for block
|
|
|
|
DECLARE_ALIGNED_16(float, transform_coeffs[AC3_MAX_CHANNELS][BLOCK_SIZE]); //transform coefficients
|
|
|
|
/* For IMDCT. */
|
|
MDCTContext imdct_512; //for 512 sample imdct transform
|
|
MDCTContext imdct_256; //for 256 sample imdct transform
|
|
DSPContext dsp; //for optimization
|
|
|
|
DECLARE_ALIGNED_16(float, output[AC3_MAX_CHANNELS][BLOCK_SIZE]); //output after imdct transform and windowing
|
|
DECLARE_ALIGNED_16(float, delay[AC3_MAX_CHANNELS][BLOCK_SIZE]); //delay - added to the next block
|
|
DECLARE_ALIGNED_16(float, tmp_imdct[BLOCK_SIZE]); //temporary storage for imdct transform
|
|
DECLARE_ALIGNED_16(float, tmp_output[BLOCK_SIZE * 2]); //temporary storage for output before windowing
|
|
DECLARE_ALIGNED_16(float, window[BLOCK_SIZE]); //window coefficients
|
|
|
|
/* Miscellaneous. */
|
|
GetBitContext gb;
|
|
AVRandomState dith_state; //for dither generation
|
|
} AC3DecodeContext;
|
|
|
|
/*********** BEGIN INIT HELPER FUNCTIONS ***********/
|
|
/**
|
|
* Generate a Kaiser-Bessel Derived Window.
|
|
*/
|
|
static void ac3_window_init(float *window)
|
|
{
|
|
int i, j;
|
|
double sum = 0.0, bessel, tmp;
|
|
double local_window[256];
|
|
double alpha2 = (5.0 * M_PI / 256.0) * (5.0 * M_PI / 256.0);
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
tmp = i * (256 - i) * alpha2;
|
|
bessel = 1.0;
|
|
for (j = 100; j > 0; j--) /* defaul to 100 iterations */
|
|
bessel = bessel * tmp / (j * j) + 1;
|
|
sum += bessel;
|
|
local_window[i] = sum;
|
|
}
|
|
|
|
sum++;
|
|
for (i = 0; i < 256; i++)
|
|
window[i] = sqrt(local_window[i] / sum);
|
|
}
|
|
|
|
/*
|
|
* Generate quantizer tables.
|
|
*/
|
|
static void generate_quantizers_table(int16_t quantizers[], int level, int length)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < length; i++)
|
|
quantizers[i] = ((2 * i - level + 1) << 15) / level;
|
|
}
|
|
|
|
static void generate_quantizers_table_1(int16_t quantizers[], int level, int length1, int length2, int size)
|
|
{
|
|
int i, j;
|
|
int16_t v;
|
|
|
|
for (i = 0; i < length1; i++) {
|
|
v = ((2 * i - level + 1) << 15) / level;
|
|
for (j = 0; j < length2; j++)
|
|
quantizers[i * length2 + j] = v;
|
|
}
|
|
|
|
for (i = length1 * length2; i < size; i++)
|
|
quantizers[i] = 0;
|
|
}
|
|
|
|
static void generate_quantizers_table_2(int16_t quantizers[], int level, int length1, int length2, int size)
|
|
{
|
|
int i, j;
|
|
int16_t v;
|
|
|
|
for (i = 0; i < length1; i++) {
|
|
v = ((2 * (i % level) - level + 1) << 15) / level;
|
|
for (j = 0; j < length2; j++)
|
|
quantizers[i * length2 + j] = v;
|
|
}
|
|
|
|
for (i = length1 * length2; i < size; i++)
|
|
quantizers[i] = 0;
|
|
|
|
}
|
|
|
|
static void generate_quantizers_table_3(int16_t quantizers[], int level, int length1, int length2, int size)
|
|
{
|
|
int i, j;
|
|
|
|
for (i = 0; i < length1; i++)
|
|
for (j = 0; j < length2; j++)
|
|
quantizers[i * length2 + j] = ((2 * (j % level) - level + 1) << 15) / level;
|
|
|
|
for (i = length1 * length2; i < size; i++)
|
|
quantizers[i] = 0;
|
|
}
|
|
|
|
/*
|
|
* Initialize tables at runtime.
|
|
*/
|
|
static void ac3_tables_init(void)
|
|
{
|
|
int i, j, k, l, v;
|
|
/* compute bndtab and masktab from bandsz */
|
|
k = 0;
|
|
l = 0;
|
|
for(i=0;i<50;i++) {
|
|
bndtab[i] = l;
|
|
v = ff_ac3_bndsz[i];
|
|
for(j=0;j<v;j++) masktab[k++]=i;
|
|
l += v;
|
|
}
|
|
masktab[253] = masktab[254] = masktab[255] = 0;
|
|
bndtab[50] = 0;
|
|
|
|
/* PSD Table For Mapping Exponents To PSD. */
|
|
for (i = 0; i < 25; i++)
|
|
psdtab[i] = 3072 - (i << 7);
|
|
|
|
/* Exponent Decoding Tables */
|
|
for (i = 0; i < 5; i++) {
|
|
v = i - 2;
|
|
for (j = 0; j < 25; j++)
|
|
exp_1[i * 25 + j] = v;
|
|
}
|
|
|
|
for (i = 0; i < 25; i++) {
|
|
v = (i % 5) - 2;
|
|
for (j = 0; j < 5; j++)
|
|
exp_2[i * 5 + j] = v;
|
|
}
|
|
|
|
for (i = 0; i < 25; i++) {
|
|
v = -2;
|
|
for (j = 0; j < 5; j++)
|
|
exp_3[i * 5 + j] = v++;
|
|
}
|
|
|
|
for (i = 125; i < 128; i++)
|
|
exp_1[i] = exp_2[i] = exp_3[i] = 25;
|
|
/* End Exponent Decoding Tables */
|
|
|
|
/* Quantizer ungrouping tables. */
|
|
// for level-3 quantizers
|
|
generate_quantizers_table_1(l3_quantizers_1, 3, 3, 9, 32);
|
|
generate_quantizers_table_2(l3_quantizers_2, 3, 9, 3, 32);
|
|
generate_quantizers_table_3(l3_quantizers_3, 3, 9, 3, 32);
|
|
|
|
//for level-5 quantizers
|
|
generate_quantizers_table_1(l5_quantizers_1, 5, 5, 25, 128);
|
|
generate_quantizers_table_2(l5_quantizers_2, 5, 25, 5, 128);
|
|
generate_quantizers_table_3(l5_quantizers_3, 5, 25, 5, 128);
|
|
|
|
//for level-7 quantizers
|
|
generate_quantizers_table(l7_quantizers, 7, 7);
|
|
|
|
//for level-4 quantizers
|
|
generate_quantizers_table_2(l11_quantizers_1, 11, 11, 11, 128);
|
|
generate_quantizers_table_3(l11_quantizers_2, 11, 11, 11, 128);
|
|
|
|
//for level-15 quantizers
|
|
generate_quantizers_table(l15_quantizers, 15, 15);
|
|
/* End Quantizer ungrouping tables. */
|
|
|
|
//generate scale factors
|
|
for (i = 0; i < 25; i++)
|
|
scale_factors[i] = pow(2.0, -(i + 15));
|
|
}
|
|
|
|
|
|
static int ac3_decode_init(AVCodecContext *avctx)
|
|
{
|
|
AC3DecodeContext *ctx = avctx->priv_data;
|
|
|
|
ac3_common_init();
|
|
ac3_tables_init();
|
|
ff_mdct_init(&ctx->imdct_256, 8, 1);
|
|
ff_mdct_init(&ctx->imdct_512, 9, 1);
|
|
ac3_window_init(ctx->window);
|
|
dsputil_init(&ctx->dsp, avctx);
|
|
av_init_random(0, &ctx->dith_state);
|
|
|
|
return 0;
|
|
}
|
|
/*********** END INIT FUNCTIONS ***********/
|
|
|
|
/* Synchronize to ac3 bitstream.
|
|
* This function searches for the syncword '0xb77'.
|
|
*
|
|
* @param buf Pointer to "probable" ac3 bitstream buffer
|
|
* @param buf_size Size of buffer
|
|
* @return Returns the position where syncword is found, -1 if no syncword is found
|
|
*/
|
|
static int ac3_synchronize(uint8_t *buf, int buf_size)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < buf_size - 1; i++)
|
|
if (buf[i] == 0x0b && buf[i + 1] == 0x77)
|
|
return i;
|
|
|
|
return -1;
|
|
}
|
|
|
|
/* Parse the 'sync_info' from the ac3 bitstream.
|
|
* This function extracts the sync_info from ac3 bitstream.
|
|
* GetBitContext within AC3DecodeContext must point to
|
|
* start of the synchronized ac3 bitstream.
|
|
*
|
|
* @param ctx AC3DecodeContext
|
|
* @return Returns framesize, returns 0 if fscod, frmsizecod or bsid is not valid
|
|
*/
|
|
static int ac3_parse_sync_info(AC3DecodeContext *ctx)
|
|
{
|
|
GetBitContext *gb = &ctx->gb;
|
|
int frmsizecod, bsid;
|
|
|
|
skip_bits(gb, 16); //skip the sync_word, sync_info->sync_word = get_bits(gb, 16);
|
|
ctx->crc1 = get_bits(gb, 16);
|
|
ctx->fscod = get_bits(gb, 2);
|
|
if (ctx->fscod == 0x03)
|
|
return 0;
|
|
frmsizecod = get_bits(gb, 6);
|
|
if (frmsizecod >= 38)
|
|
return 0;
|
|
ctx->sampling_rate = ff_ac3_freqs[ctx->fscod];
|
|
ctx->bit_rate = ff_ac3_bitratetab[frmsizecod >> 1];
|
|
|
|
/* we include it here in order to determine validity of ac3 frame */
|
|
bsid = get_bits(gb, 5);
|
|
if (bsid > 0x08)
|
|
return 0;
|
|
skip_bits(gb, 3); //skip the bsmod, bsi->bsmod = get_bits(gb, 3);
|
|
|
|
switch (ctx->fscod) {
|
|
case 0x00:
|
|
ctx->frame_size = 4 * ctx->bit_rate;
|
|
return ctx->frame_size;
|
|
case 0x01:
|
|
ctx->frame_size = 2 * (320 * ctx->bit_rate / 147 + (frmsizecod & 1));
|
|
return ctx->frame_size;
|
|
case 0x02:
|
|
ctx->frame_size = 6 * ctx->bit_rate;
|
|
return ctx->frame_size;
|
|
}
|
|
|
|
/* never reached */
|
|
return 0;
|
|
}
|
|
|
|
/* Parse bsi from ac3 bitstream.
|
|
* This function extracts the bitstream information (bsi) from ac3 bitstream.
|
|
*
|
|
* @param ctx AC3DecodeContext after processed by ac3_parse_sync_info
|
|
*/
|
|
static void ac3_parse_bsi(AC3DecodeContext *ctx)
|
|
{
|
|
GetBitContext *gb = &ctx->gb;
|
|
int i;
|
|
|
|
ctx->cmixlev = 0;
|
|
ctx->surmixlev = 0;
|
|
ctx->dsurmod = 0;
|
|
ctx->nfchans = 0;
|
|
ctx->cpldeltbae = DBA_NONE;
|
|
ctx->cpldeltnseg = 0;
|
|
for (i = 0; i < 5; i++) {
|
|
ctx->deltbae[i] = DBA_NONE;
|
|
ctx->deltnseg[i] = 0;
|
|
}
|
|
ctx->dynrng = 1.0;
|
|
ctx->dynrng2 = 1.0;
|
|
|
|
ctx->acmod = get_bits(gb, 3);
|
|
ctx->nfchans = nfchans_tbl[ctx->acmod];
|
|
|
|
if (ctx->acmod & 0x01 && ctx->acmod != 0x01)
|
|
ctx->cmixlev = get_bits(gb, 2);
|
|
if (ctx->acmod & 0x04)
|
|
ctx->surmixlev = get_bits(gb, 2);
|
|
if (ctx->acmod == 0x02)
|
|
ctx->dsurmod = get_bits(gb, 2);
|
|
|
|
ctx->lfeon = get_bits1(gb);
|
|
|
|
i = !(ctx->acmod);
|
|
do {
|
|
skip_bits(gb, 5); //skip dialog normalization
|
|
if (get_bits1(gb))
|
|
skip_bits(gb, 8); //skip compression
|
|
if (get_bits1(gb))
|
|
skip_bits(gb, 8); //skip language code
|
|
if (get_bits1(gb))
|
|
skip_bits(gb, 7); //skip audio production information
|
|
} while (i--);
|
|
|
|
skip_bits(gb, 2); //skip copyright bit and original bitstream bit
|
|
|
|
if (get_bits1(gb))
|
|
skip_bits(gb, 14); //skip timecode1
|
|
if (get_bits1(gb))
|
|
skip_bits(gb, 14); //skip timecode2
|
|
|
|
if (get_bits1(gb)) {
|
|
i = get_bits(gb, 6); //additional bsi length
|
|
do {
|
|
skip_bits(gb, 8);
|
|
} while(i--);
|
|
}
|
|
}
|
|
|
|
/* Decodes the grouped exponents.
|
|
* This function decodes the coded exponents according to exponent strategy
|
|
* and stores them in the decoded exponents buffer.
|
|
*
|
|
* @param gb GetBitContext which points to start of coded exponents
|
|
* @param expstr Exponent coding strategy
|
|
* @param ngrps Number of grouped exponetns
|
|
* @param absexp Absolute exponent
|
|
* @param dexps Decoded exponents are stored in dexps
|
|
* @return Returns 0 if exponents are decoded successfully, -1 if error occurs
|
|
*/
|
|
static int decode_exponents(GetBitContext *gb, int expstr, int ngrps, uint8_t absexp, uint8_t *dexps)
|
|
{
|
|
int exps;
|
|
|
|
while (ngrps--) {
|
|
exps = get_bits(gb, 7);
|
|
|
|
absexp += exp_1[exps];
|
|
if (absexp > 24) {
|
|
av_log(NULL, AV_LOG_ERROR, "Absolute Exponent > 24, ngrp = %d\n", ngrps);
|
|
return -ngrps;
|
|
}
|
|
switch (expstr) {
|
|
case EXP_D45:
|
|
*(dexps++) = absexp;
|
|
*(dexps++) = absexp;
|
|
case EXP_D25:
|
|
*(dexps++) = absexp;
|
|
case EXP_D15:
|
|
*(dexps++) = absexp;
|
|
}
|
|
|
|
absexp += exp_2[exps];
|
|
if (absexp > 24) {
|
|
av_log(NULL, AV_LOG_ERROR, "Absolute Exponent > 24, ngrp = %d\n", ngrps);
|
|
return -ngrps;
|
|
}
|
|
switch (expstr) {
|
|
case EXP_D45:
|
|
*(dexps++) = absexp;
|
|
*(dexps++) = absexp;
|
|
case EXP_D25:
|
|
*(dexps++) = absexp;
|
|
case EXP_D15:
|
|
*(dexps++) = absexp;
|
|
}
|
|
|
|
absexp += exp_3[exps];
|
|
if (absexp > 24) {
|
|
av_log(NULL, AV_LOG_ERROR, "Absolute Exponent > 24, ngrp = %d\n", ngrps);
|
|
return -ngrps;
|
|
}
|
|
switch (expstr) {
|
|
case EXP_D45:
|
|
*(dexps++) = absexp;
|
|
*(dexps++) = absexp;
|
|
case EXP_D25:
|
|
*(dexps++) = absexp;
|
|
case EXP_D15:
|
|
*(dexps++) = absexp;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*********** HELPER FUNCTIONS FOR BIT ALLOCATION ***********/
|
|
static inline int logadd(int a, int b)
|
|
{
|
|
int c = a - b;
|
|
int address;
|
|
|
|
address = FFMIN((FFABS(c) >> 1), 255);
|
|
|
|
if (c >= 0)
|
|
return (a + ff_ac3_latab[address]);
|
|
else
|
|
return (b + ff_ac3_latab[address]);
|
|
}
|
|
|
|
static inline int calc_lowcomp(int a, int b0, int b1, int bin)
|
|
{
|
|
if (bin < 7) {
|
|
if ((b0 + 256) == b1)
|
|
a = 384;
|
|
else if (b0 > b1)
|
|
a = FFMAX(0, (a - 64));
|
|
}
|
|
else if (bin < 20) {
|
|
if ((b0 + 256) == b1)
|
|
a = 320;
|
|
else if (b0 > b1)
|
|
a = FFMAX(0, (a - 64));
|
|
}
|
|
else
|
|
a = FFMAX(0, (a - 128));
|
|
|
|
return a;
|
|
}
|
|
/*********** END HELPER FUNCTIONS FOR BIT ALLOCATION ***********/
|
|
|
|
/* Performs bit allocation.
|
|
* This function performs bit allocation for the requested chanenl.
|
|
*/
|
|
static void do_bit_allocation(AC3DecodeContext *ctx, int chnl)
|
|
{
|
|
int16_t psd[256], bndpsd[50], excite[50], mask[50], delta;
|
|
int sdecay, fdecay, sgain, dbknee, floor;
|
|
int lowcomp = 0, fgain = 0, snroffset = 0, fastleak = 0, slowleak = 0, do_delta = 0;
|
|
int start = 0, end = 0, bin = 0, i = 0, j = 0, k = 0, lastbin = 0, bndstrt = 0;
|
|
int bndend = 0, begin = 0, deltnseg = 0, band = 0, seg = 0, address = 0;
|
|
int fscod = ctx->fscod;
|
|
uint8_t *deltoffst = 0, *deltlen = 0, *deltba = 0;
|
|
uint8_t *exps = 0, *bap = 0;
|
|
|
|
/* initialization */
|
|
sdecay = ff_sdecaytab[ctx->sdcycod];
|
|
fdecay = ff_fdecaytab[ctx->fdcycod];
|
|
sgain = ff_sgaintab[ctx->sgaincod];
|
|
dbknee = ff_dbkneetab[ctx->dbpbcod];
|
|
floor = ff_floortab[ctx->floorcod];
|
|
|
|
if (chnl == 5) {
|
|
start = ctx->cplstrtmant;
|
|
end = ctx->cplendmant;
|
|
fgain = ff_fgaintab[ctx->cplfgaincod];
|
|
snroffset = (((ctx->csnroffst - 15) << 4) + ctx->cplfsnroffst) << 2;
|
|
fastleak = (ctx->cplfleak << 8) + 768;
|
|
slowleak = (ctx->cplsleak << 8) + 768;
|
|
exps = ctx->dcplexps;
|
|
bap = ctx->cplbap;
|
|
if (ctx->cpldeltbae == DBA_NEW || ctx->deltbae == DBA_REUSE) {
|
|
do_delta = 1;
|
|
deltnseg = ctx->cpldeltnseg;
|
|
deltoffst = ctx->cpldeltoffst;
|
|
deltlen = ctx->cpldeltlen;
|
|
deltba = ctx->cpldeltba;
|
|
}
|
|
}
|
|
else if (chnl == 6) {
|
|
start = 0;
|
|
end = 7;
|
|
lowcomp = 0;
|
|
fastleak = 0;
|
|
slowleak = 0;
|
|
fgain = ff_fgaintab[ctx->lfefgaincod];
|
|
snroffset = (((ctx->csnroffst - 15) << 4) + ctx->lfefsnroffst) << 2;
|
|
exps = ctx->dlfeexps;
|
|
bap = ctx->lfebap;
|
|
}
|
|
else {
|
|
start = 0;
|
|
end = ctx->endmant[chnl];
|
|
lowcomp = 0;
|
|
fastleak = 0;
|
|
slowleak = 0;
|
|
fgain = ff_fgaintab[ctx->fgaincod[chnl]];
|
|
snroffset = (((ctx->csnroffst - 15) << 4) + ctx->fsnroffst[chnl]) << 2;
|
|
exps = ctx->dexps[chnl];
|
|
bap = ctx->bap[chnl];
|
|
if (ctx->deltbae[chnl] == DBA_NEW || ctx->deltbae[chnl] == DBA_REUSE) {
|
|
do_delta = 1;
|
|
deltnseg = ctx->deltnseg[chnl];
|
|
deltoffst = ctx->deltoffst[chnl];
|
|
deltlen = ctx->deltlen[chnl];
|
|
deltba = ctx->deltba[chnl];
|
|
}
|
|
}
|
|
|
|
for (bin = start; bin < end; bin++) /* exponent mapping into psd */
|
|
psd[bin] = psdtab[exps[bin]];
|
|
|
|
/* psd integration */
|
|
j = start;
|
|
k = masktab[start];
|
|
do {
|
|
lastbin = FFMIN((bndtab[k] + ff_ac3_bndsz[k]), end);
|
|
bndpsd[k] = psd[j];
|
|
j++;
|
|
for (i = j; i < lastbin; i++) {
|
|
bndpsd[k] = logadd(bndpsd[k], psd[j]);
|
|
j++;
|
|
}
|
|
k++;
|
|
} while (end > lastbin);
|
|
|
|
/* compute the excite function */
|
|
bndstrt = masktab[start];
|
|
bndend = masktab[end - 1] + 1;
|
|
if (bndstrt == 0) {
|
|
lowcomp = calc_lowcomp(lowcomp, bndpsd[0], bndpsd[1], 0);
|
|
excite[0] = bndpsd[0] - fgain - lowcomp;
|
|
lowcomp = calc_lowcomp(lowcomp, bndpsd[1], bndpsd[2], 1);
|
|
excite[1] = bndpsd[1] - fgain - lowcomp;
|
|
begin = 7;
|
|
for (bin = 2; bin < 7; bin++) {
|
|
if ((bndend != 7) || (bin != 6))
|
|
lowcomp = calc_lowcomp(lowcomp, bndpsd[bin], bndpsd[bin + 1], bin);
|
|
fastleak = bndpsd[bin] - fgain;
|
|
slowleak = bndpsd[bin] - sgain;
|
|
excite[bin] = fastleak - lowcomp;
|
|
if ((bndend != 7) || (bin != 6))
|
|
if (bndpsd[bin] <= bndpsd[bin + 1]) {
|
|
begin = bin + 1;
|
|
break;
|
|
}
|
|
}
|
|
for (bin = begin; bin < FFMIN(bndend, 22); bin++) {
|
|
if ((bndend != 7) || (bin != 6))
|
|
lowcomp = calc_lowcomp(lowcomp, bndpsd[bin], bndpsd[bin + 1], bin);
|
|
fastleak -= fdecay;
|
|
fastleak = FFMAX(fastleak, (bndpsd[bin] - fgain));
|
|
slowleak -= sdecay;
|
|
slowleak = FFMAX(slowleak, (bndpsd[bin] - sgain));
|
|
excite[bin] = FFMAX((fastleak - lowcomp), slowleak);
|
|
}
|
|
begin = 22;
|
|
}
|
|
else {
|
|
begin = bndstrt;
|
|
}
|
|
for (bin = begin; bin < bndend; bin++) {
|
|
fastleak -= fdecay;
|
|
fastleak = FFMAX(fastleak, (bndpsd[bin] - fgain));
|
|
slowleak -= sdecay;
|
|
slowleak = FFMAX(slowleak, (bndpsd[bin] - sgain));
|
|
excite[bin] = FFMAX(fastleak, slowleak);
|
|
}
|
|
|
|
/* compute the masking curve */
|
|
for (bin = bndstrt; bin < bndend; bin++) {
|
|
if (bndpsd[bin] < dbknee)
|
|
excite[bin] += ((dbknee - bndpsd[bin]) >> 2);
|
|
mask[bin] = FFMAX(excite[bin], ff_ac3_hth[bin][fscod]);
|
|
}
|
|
|
|
/* apply the delta bit allocation */
|
|
if (do_delta) {
|
|
band = 0;
|
|
for (seg = 0; seg < deltnseg + 1; seg++) {
|
|
band += deltoffst[seg];
|
|
if (deltba[seg] >= 4)
|
|
delta = (deltba[seg] - 3) << 7;
|
|
else
|
|
delta = (deltba[seg] - 4) << 7;
|
|
for (k = 0; k < deltlen[seg]; k++) {
|
|
mask[band] += delta;
|
|
band++;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*compute the bit allocation */
|
|
i = start;
|
|
j = masktab[start];
|
|
do {
|
|
lastbin = FFMIN((bndtab[j] + ff_ac3_bndsz[j]), end);
|
|
mask[j] -= snroffset;
|
|
mask[j] -= floor;
|
|
if (mask[j] < 0)
|
|
mask[j] = 0;
|
|
mask[j] &= 0x1fe0;
|
|
mask[j] += floor;
|
|
for (k = i; k < lastbin; k++) {
|
|
address = (psd[i] - mask[j]) >> 5;
|
|
address = FFMIN(63, (FFMAX(0, address)));
|
|
bap[i] = ff_ac3_baptab[address];
|
|
i++;
|
|
}
|
|
j++;
|
|
} while (end > lastbin);
|
|
}
|
|
|
|
/* Check if snroffsets are zero. */
|
|
static int is_snr_offsets_zero(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
|
|
if ((ctx->csnroffst) || (ctx->cplinu && ctx->cplfsnroffst) ||
|
|
(ctx->lfeon && ctx->lfefsnroffst))
|
|
return 0;
|
|
|
|
for (i = 0; i < ctx->nfchans; i++)
|
|
if (ctx->fsnroffst[i])
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
typedef struct { /* grouped mantissas for 3-level 5-leve and 11-level quantization */
|
|
int16_t l3_quantizers[3];
|
|
int16_t l5_quantizers[3];
|
|
int16_t l11_quantizers[2];
|
|
int l3ptr;
|
|
int l5ptr;
|
|
int l11ptr;
|
|
} mant_groups;
|
|
|
|
#define TRANSFORM_COEFF(tc, m, e, f) (tc) = (m) * (f)[(e)]
|
|
|
|
/* Get the transform coefficients for coupling channel and uncouple channels.
|
|
* The coupling transform coefficients starts at the the cplstrtmant, which is
|
|
* equal to endmant[ch] for fbw channels. Hence we can uncouple channels before
|
|
* getting transform coefficients for the channel.
|
|
*/
|
|
static int get_transform_coeffs_cpling(AC3DecodeContext *ctx, mant_groups *m)
|
|
{
|
|
GetBitContext *gb = &ctx->gb;
|
|
int ch, start, end, cplbndstrc, bnd, gcode, tbap;
|
|
float cplcos[5], cplcoeff;
|
|
uint8_t *exps = ctx->dcplexps;
|
|
uint8_t *bap = ctx->cplbap;
|
|
|
|
cplbndstrc = ctx->cplbndstrc;
|
|
start = ctx->cplstrtmant;
|
|
bnd = 0;
|
|
|
|
while (start < ctx->cplendmant) {
|
|
end = start + 12;
|
|
while (cplbndstrc & 1) {
|
|
end += 12;
|
|
cplbndstrc >>= 1;
|
|
}
|
|
cplbndstrc >>= 1;
|
|
for (ch = 0; ch < ctx->nfchans; ch++)
|
|
cplcos[ch] = ctx->chcoeffs[ch] * ctx->cplco[ch][bnd];
|
|
bnd++;
|
|
|
|
while (start < end) {
|
|
tbap = bap[start];
|
|
switch(tbap) {
|
|
case 0:
|
|
for (ch = 0; ch < ctx->nfchans; ch++)
|
|
if (((ctx->chincpl) >> ch) & 1) {
|
|
if ((ctx->dithflag >> ch) & 1) {
|
|
TRANSFORM_COEFF(cplcoeff, av_random(&ctx->dith_state) & 0xFFFF, exps[start], scale_factors);
|
|
ctx->transform_coeffs[ch + 1][start] = cplcoeff * cplcos[ch] * LEVEL_MINUS_3DB;
|
|
} else
|
|
ctx->transform_coeffs[ch + 1][start] = 0;
|
|
}
|
|
start++;
|
|
continue;
|
|
case 1:
|
|
if (m->l3ptr > 2) {
|
|
gcode = get_bits(gb, 5);
|
|
m->l3_quantizers[0] = l3_quantizers_1[gcode];
|
|
m->l3_quantizers[1] = l3_quantizers_2[gcode];
|
|
m->l3_quantizers[2] = l3_quantizers_3[gcode];
|
|
m->l3ptr = 0;
|
|
}
|
|
TRANSFORM_COEFF(cplcoeff, m->l3_quantizers[m->l3ptr++], exps[start], scale_factors);
|
|
break;
|
|
|
|
case 2:
|
|
if (m->l5ptr > 2) {
|
|
gcode = get_bits(gb, 7);
|
|
m->l5_quantizers[0] = l5_quantizers_1[gcode];
|
|
m->l5_quantizers[1] = l5_quantizers_2[gcode];
|
|
m->l5_quantizers[2] = l5_quantizers_3[gcode];
|
|
m->l5ptr = 0;
|
|
}
|
|
TRANSFORM_COEFF(cplcoeff, m->l5_quantizers[m->l5ptr++], exps[start], scale_factors);
|
|
break;
|
|
|
|
case 3:
|
|
TRANSFORM_COEFF(cplcoeff, l7_quantizers[get_bits(gb, 3)], exps[start], scale_factors);
|
|
break;
|
|
|
|
case 4:
|
|
if (m->l11ptr > 1) {
|
|
gcode = get_bits(gb, 7);
|
|
m->l11_quantizers[0] = l11_quantizers_1[gcode];
|
|
m->l11_quantizers[1] = l11_quantizers_2[gcode];
|
|
m->l11ptr = 0;
|
|
}
|
|
TRANSFORM_COEFF(cplcoeff, m->l11_quantizers[m->l11ptr++], exps[start], scale_factors);
|
|
break;
|
|
|
|
case 5:
|
|
TRANSFORM_COEFF(cplcoeff, l15_quantizers[get_bits(gb, 4)], exps[start], scale_factors);
|
|
break;
|
|
|
|
default:
|
|
TRANSFORM_COEFF(cplcoeff, get_sbits(gb, qntztab[tbap]) << (16 - qntztab[tbap]),
|
|
exps[start], scale_factors);
|
|
}
|
|
for (ch = 0; ch < ctx->nfchans; ch++)
|
|
if ((ctx->chincpl >> ch) & 1)
|
|
ctx->transform_coeffs[ch + 1][start] = cplcoeff * cplcos[ch];
|
|
start++;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Get the transform coefficients for particular channel */
|
|
static int get_transform_coeffs_ch(AC3DecodeContext *ctx, int ch_index, mant_groups *m)
|
|
{
|
|
GetBitContext *gb = &ctx->gb;
|
|
int i, gcode, tbap, dithflag, end;
|
|
uint8_t *exps;
|
|
uint8_t *bap;
|
|
float *coeffs;
|
|
float factors[25];
|
|
|
|
for (i = 0; i < 25; i++)
|
|
factors[i] = scale_factors[i] * ctx->chcoeffs[ch_index];
|
|
|
|
if (ch_index != -1) { /* fbw channels */
|
|
dithflag = (ctx->dithflag >> ch_index) & 1;
|
|
exps = ctx->dexps[ch_index];
|
|
bap = ctx->bap[ch_index];
|
|
coeffs = ctx->transform_coeffs[ch_index + 1];
|
|
end = ctx->endmant[ch_index];
|
|
} else if (ch_index == -1) {
|
|
dithflag = 0;
|
|
exps = ctx->dlfeexps;
|
|
bap = ctx->lfebap;
|
|
coeffs = ctx->transform_coeffs[0];
|
|
end = 7;
|
|
}
|
|
|
|
|
|
for (i = 0; i < end; i++) {
|
|
tbap = bap[i];
|
|
switch (tbap) {
|
|
case 0:
|
|
if (!dithflag) {
|
|
coeffs[i] = 0;
|
|
continue;
|
|
}
|
|
else {
|
|
TRANSFORM_COEFF(coeffs[i], av_random(&ctx->dith_state) & 0xFFFF, exps[i], factors);
|
|
coeffs[i] *= LEVEL_MINUS_3DB;
|
|
continue;
|
|
}
|
|
|
|
case 1:
|
|
if (m->l3ptr > 2) {
|
|
gcode = get_bits(gb, 5);
|
|
m->l3_quantizers[0] = l3_quantizers_1[gcode];
|
|
m->l3_quantizers[1] = l3_quantizers_2[gcode];
|
|
m->l3_quantizers[2] = l3_quantizers_3[gcode];
|
|
m->l3ptr = 0;
|
|
}
|
|
TRANSFORM_COEFF(coeffs[i], m->l3_quantizers[m->l3ptr++], exps[i], factors);
|
|
continue;
|
|
|
|
case 2:
|
|
if (m->l5ptr > 2) {
|
|
gcode = get_bits(gb, 7);
|
|
m->l5_quantizers[0] = l5_quantizers_1[gcode];
|
|
m->l5_quantizers[1] = l5_quantizers_2[gcode];
|
|
m->l5_quantizers[2] = l5_quantizers_3[gcode];
|
|
m->l5ptr = 0;
|
|
}
|
|
TRANSFORM_COEFF(coeffs[i], m->l5_quantizers[m->l5ptr++], exps[i], factors);
|
|
continue;
|
|
|
|
case 3:
|
|
TRANSFORM_COEFF(coeffs[i], l7_quantizers[get_bits(gb, 3)], exps[i], factors);
|
|
continue;
|
|
|
|
case 4:
|
|
if (m->l11ptr > 1) {
|
|
gcode = get_bits(gb, 7);
|
|
m->l11_quantizers[0] = l11_quantizers_1[gcode];
|
|
m->l11_quantizers[1] = l11_quantizers_2[gcode];
|
|
m->l11ptr = 0;
|
|
}
|
|
TRANSFORM_COEFF(coeffs[i], m->l11_quantizers[m->l11ptr++], exps[i], factors);
|
|
continue;
|
|
|
|
case 5:
|
|
TRANSFORM_COEFF(coeffs[i], l15_quantizers[get_bits(gb, 4)], exps[i], factors);
|
|
continue;
|
|
|
|
default:
|
|
TRANSFORM_COEFF(coeffs[i], get_sbits(gb, qntztab[tbap]) << (16 - qntztab[tbap]), exps[i], factors);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Get the transform coefficients.
|
|
* This function extracts the tranform coefficients form the ac3 bitstream.
|
|
* This function is called after bit allocation is performed.
|
|
*/
|
|
static int get_transform_coeffs(AC3DecodeContext * ctx)
|
|
{
|
|
int i, end;
|
|
int got_cplchan = 0;
|
|
mant_groups m;
|
|
|
|
m.l3ptr = m.l5ptr = m.l11ptr = 3;
|
|
|
|
for (i = 0; i < ctx->nfchans; i++) {
|
|
/* transform coefficients for individual channel */
|
|
if (get_transform_coeffs_ch(ctx, i, &m))
|
|
return -1;
|
|
/* tranform coefficients for coupling channels */
|
|
if ((ctx->chincpl >> i) & 1) {
|
|
if (!got_cplchan) {
|
|
if (get_transform_coeffs_cpling(ctx, &m)) {
|
|
av_log(NULL, AV_LOG_ERROR, "error in decoupling channels\n");
|
|
return -1;
|
|
}
|
|
got_cplchan = 1;
|
|
}
|
|
end = ctx->cplendmant;
|
|
} else
|
|
end = ctx->endmant[i];
|
|
do
|
|
ctx->transform_coeffs[i + 1][end] = 0;
|
|
while(++end < 256);
|
|
}
|
|
if (ctx->lfeon) {
|
|
if (get_transform_coeffs_ch(ctx, -1, &m))
|
|
return -1;
|
|
for (i = 7; i < 256; i++) {
|
|
ctx->transform_coeffs[0][i] = 0;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Rematrixing routines. */
|
|
static void do_rematrixing1(AC3DecodeContext *ctx, int start, int end)
|
|
{
|
|
float tmp0, tmp1;
|
|
|
|
while (start < end) {
|
|
tmp0 = ctx->transform_coeffs[1][start];
|
|
tmp1 = ctx->transform_coeffs[2][start];
|
|
ctx->transform_coeffs[1][start] = tmp0 + tmp1;
|
|
ctx->transform_coeffs[2][start] = tmp0 - tmp1;
|
|
start++;
|
|
}
|
|
}
|
|
|
|
static void do_rematrixing(AC3DecodeContext *ctx)
|
|
{
|
|
int bnd1 = 13, bnd2 = 25, bnd3 = 37, bnd4 = 61;
|
|
int end, bndend;
|
|
|
|
end = FFMIN(ctx->endmant[0], ctx->endmant[1]);
|
|
|
|
if (ctx->rematflg & 1)
|
|
do_rematrixing1(ctx, bnd1, bnd2);
|
|
|
|
if (ctx->rematflg & 2)
|
|
do_rematrixing1(ctx, bnd2, bnd3);
|
|
|
|
bndend = bnd4;
|
|
if (bndend > end) {
|
|
bndend = end;
|
|
if (ctx->rematflg & 4)
|
|
do_rematrixing1(ctx, bnd3, bndend);
|
|
} else {
|
|
if (ctx->rematflg & 4)
|
|
do_rematrixing1(ctx, bnd3, bnd4);
|
|
if (ctx->rematflg & 8)
|
|
do_rematrixing1(ctx, bnd4, end);
|
|
}
|
|
}
|
|
|
|
/* This function sets the normalized channel coefficients.
|
|
* Transform coefficients are multipllied by the channel
|
|
* coefficients to get normalized transform coefficients.
|
|
*/
|
|
static void get_downmix_coeffs(AC3DecodeContext *ctx)
|
|
{
|
|
int from = ctx->acmod;
|
|
int to = ctx->blkoutput;
|
|
float clev = clevs[ctx->cmixlev];
|
|
float slev = slevs[ctx->surmixlev];
|
|
float nf = 1.0; //normalization factor for downmix coeffs
|
|
int i;
|
|
|
|
if (!ctx->acmod) {
|
|
ctx->chcoeffs[0] = 2 * ctx->dynrng;
|
|
ctx->chcoeffs[1] = 2 * ctx->dynrng2;
|
|
} else {
|
|
for (i = 0; i < ctx->nfchans; i++)
|
|
ctx->chcoeffs[i] = 2 * ctx->dynrng;
|
|
}
|
|
|
|
if (to == AC3_OUTPUT_UNMODIFIED)
|
|
return;
|
|
|
|
switch (from) {
|
|
case AC3_ACMOD_DUALMONO:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
case AC3_OUTPUT_STEREO: /* We Assume that sum of both mono channels is requested */
|
|
nf = 0.5;
|
|
ctx->chcoeffs[0] *= nf;
|
|
ctx->chcoeffs[1] *= nf;
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_MONO:
|
|
switch (to) {
|
|
case AC3_OUTPUT_STEREO:
|
|
nf = LEVEL_MINUS_3DB;
|
|
ctx->chcoeffs[0] *= nf;
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_STEREO:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
nf = LEVEL_MINUS_3DB;
|
|
ctx->chcoeffs[0] *= nf;
|
|
ctx->chcoeffs[1] *= nf;
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_3F:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
nf = LEVEL_MINUS_3DB / (1.0 + clev);
|
|
ctx->chcoeffs[0] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[2] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[1] *= ((nf * clev * LEVEL_MINUS_3DB) / 2.0);
|
|
break;
|
|
case AC3_OUTPUT_STEREO:
|
|
nf = 1.0 / (1.0 + clev);
|
|
ctx->chcoeffs[0] *= nf;
|
|
ctx->chcoeffs[2] *= nf;
|
|
ctx->chcoeffs[1] *= (nf * clev);
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_2F1R:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
nf = 2.0 * LEVEL_MINUS_3DB / (2.0 + slev);
|
|
ctx->chcoeffs[0] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[1] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[2] *= (nf * slev * LEVEL_MINUS_3DB);
|
|
break;
|
|
case AC3_OUTPUT_STEREO:
|
|
nf = 1.0 / (1.0 + (slev * LEVEL_MINUS_3DB));
|
|
ctx->chcoeffs[0] *= nf;
|
|
ctx->chcoeffs[1] *= nf;
|
|
ctx->chcoeffs[2] *= (nf * slev * LEVEL_MINUS_3DB);
|
|
break;
|
|
case AC3_OUTPUT_DOLBY:
|
|
nf = 1.0 / (1.0 + LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[0] *= nf;
|
|
ctx->chcoeffs[1] *= nf;
|
|
ctx->chcoeffs[2] *= (nf * LEVEL_MINUS_3DB);
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_3F1R:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
nf = LEVEL_MINUS_3DB / (1.0 + clev + (slev / 2.0));
|
|
ctx->chcoeffs[0] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[2] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[1] *= (nf * clev * LEVEL_PLUS_3DB);
|
|
ctx->chcoeffs[3] *= (nf * slev * LEVEL_MINUS_3DB);
|
|
break;
|
|
case AC3_OUTPUT_STEREO:
|
|
nf = 1.0 / (1.0 + clev + (slev * LEVEL_MINUS_3DB));
|
|
ctx->chcoeffs[0] *= nf;
|
|
ctx->chcoeffs[2] *= nf;
|
|
ctx->chcoeffs[1] *= (nf * clev);
|
|
ctx->chcoeffs[3] *= (nf * slev * LEVEL_MINUS_3DB);
|
|
break;
|
|
case AC3_OUTPUT_DOLBY:
|
|
nf = 1.0 / (1.0 + (2.0 * LEVEL_MINUS_3DB));
|
|
ctx->chcoeffs[0] *= nf;
|
|
ctx->chcoeffs[1] *= nf;
|
|
ctx->chcoeffs[1] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[3] *= (nf * LEVEL_MINUS_3DB);
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_2F2R:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
nf = LEVEL_MINUS_3DB / (1.0 + slev);
|
|
ctx->chcoeffs[0] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[1] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[2] *= (nf * slev * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[3] *= (nf * slev * LEVEL_MINUS_3DB);
|
|
break;
|
|
case AC3_OUTPUT_STEREO:
|
|
nf = 1.0 / (1.0 + slev);
|
|
ctx->chcoeffs[0] *= nf;
|
|
ctx->chcoeffs[1] *= nf;
|
|
ctx->chcoeffs[2] *= (nf * slev);
|
|
ctx->chcoeffs[3] *= (nf * slev);
|
|
break;
|
|
case AC3_OUTPUT_DOLBY:
|
|
nf = 1.0 / (1.0 + (2.0 * LEVEL_MINUS_3DB));
|
|
ctx->chcoeffs[0] *= nf;
|
|
ctx->chcoeffs[1] *= nf;
|
|
ctx->chcoeffs[2] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[3] *= (nf * LEVEL_MINUS_3DB);
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_3F2R:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
nf = LEVEL_MINUS_3DB / (1.0 + clev + slev);
|
|
ctx->chcoeffs[0] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[2] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[1] *= (nf * clev * LEVEL_PLUS_3DB);
|
|
ctx->chcoeffs[3] *= (nf * slev * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[4] *= (nf * slev * LEVEL_MINUS_3DB);
|
|
break;
|
|
case AC3_OUTPUT_STEREO:
|
|
nf = 1.0 / (1.0 + clev + slev);
|
|
ctx->chcoeffs[0] *= nf;
|
|
ctx->chcoeffs[2] *= nf;
|
|
ctx->chcoeffs[1] *= (nf * clev);
|
|
ctx->chcoeffs[3] *= (nf * slev);
|
|
ctx->chcoeffs[4] *= (nf * slev);
|
|
break;
|
|
case AC3_OUTPUT_DOLBY:
|
|
nf = 1.0 / (1.0 + (3.0 * LEVEL_MINUS_3DB));
|
|
ctx->chcoeffs[0] *= nf;
|
|
ctx->chcoeffs[1] *= nf;
|
|
ctx->chcoeffs[1] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[3] *= (nf * LEVEL_MINUS_3DB);
|
|
ctx->chcoeffs[4] *= (nf * LEVEL_MINUS_3DB);
|
|
break;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*********** BEGIN DOWNMIX FUNCTIONS ***********/
|
|
static inline void mix_dualmono_to_mono(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++)
|
|
output[1][i] += output[2][i];
|
|
memset(output[2], 0, sizeof(output[2]));
|
|
}
|
|
|
|
static inline void mix_dualmono_to_stereo(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float tmp;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
tmp = output[1][i] + output[2][i];
|
|
output[1][i] = output[2][i] = tmp;
|
|
}
|
|
}
|
|
|
|
static inline void upmix_mono_to_stereo(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++)
|
|
output[2][i] = output[1][i];
|
|
}
|
|
|
|
static inline void mix_stereo_to_mono(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++)
|
|
output[1][i] += output[2][i];
|
|
memset(output[2], 0, sizeof(output[2]));
|
|
}
|
|
|
|
static inline void mix_3f_to_mono(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++)
|
|
output[1][i] += (output[2][i] + output[3][i]);
|
|
memset(output[2], 0, sizeof(output[2]));
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
}
|
|
|
|
static inline void mix_3f_to_stereo(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
output[1][i] += output[2][i];
|
|
output[2][i] += output[3][i];
|
|
}
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
}
|
|
|
|
static inline void mix_2f_1r_to_mono(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++)
|
|
output[1][i] += (output[2][i] + output[3][i]);
|
|
memset(output[2], 0, sizeof(output[2]));
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
|
|
}
|
|
|
|
static inline void mix_2f_1r_to_stereo(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
output[1][i] += output[2][i];
|
|
output[2][i] += output[3][i];
|
|
}
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
}
|
|
|
|
static inline void mix_2f_1r_to_dolby(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
output[1][i] -= output[3][i];
|
|
output[2][i] += output[3][i];
|
|
}
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
}
|
|
|
|
static inline void mix_3f_1r_to_mono(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++)
|
|
output[1][i] = (output[2][i] + output[3][i] + output[4][i]);
|
|
memset(output[2], 0, sizeof(output[2]));
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
memset(output[4], 0, sizeof(output[4]));
|
|
}
|
|
|
|
static inline void mix_3f_1r_to_stereo(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
output[1][i] += (output[2][i] + output[4][i]);
|
|
output[2][i] += (output[3][i] + output[4][i]);
|
|
}
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
memset(output[4], 0, sizeof(output[4]));
|
|
}
|
|
|
|
static inline void mix_3f_1r_to_dolby(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
output[1][i] += (output[2][i] - output[4][i]);
|
|
output[2][i] += (output[3][i] + output[4][i]);
|
|
}
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
memset(output[4], 0, sizeof(output[4]));
|
|
}
|
|
|
|
static inline void mix_2f_2r_to_mono(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++)
|
|
output[1][i] = (output[2][i] + output[3][i] + output[4][i]);
|
|
memset(output[2], 0, sizeof(output[2]));
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
memset(output[4], 0, sizeof(output[4]));
|
|
}
|
|
|
|
static inline void mix_2f_2r_to_stereo(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
output[1][i] += output[3][i];
|
|
output[2][i] += output[4][i];
|
|
}
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
memset(output[4], 0, sizeof(output[4]));
|
|
}
|
|
|
|
static inline void mix_2f_2r_to_dolby(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
output[1][i] -= output[3][i];
|
|
output[2][i] += output[4][i];
|
|
}
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
memset(output[4], 0, sizeof(output[4]));
|
|
}
|
|
|
|
static inline void mix_3f_2r_to_mono(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++)
|
|
output[1][i] += (output[2][i] + output[3][i] + output[4][i] + output[5][i]);
|
|
memset(output[2], 0, sizeof(output[2]));
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
memset(output[4], 0, sizeof(output[4]));
|
|
memset(output[5], 0, sizeof(output[5]));
|
|
}
|
|
|
|
static inline void mix_3f_2r_to_stereo(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
output[1][i] += (output[2][i] + output[4][i]);
|
|
output[2][i] += (output[3][i] + output[5][i]);
|
|
}
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
memset(output[4], 0, sizeof(output[4]));
|
|
memset(output[5], 0, sizeof(output[5]));
|
|
}
|
|
|
|
static inline void mix_3f_2r_to_dolby(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
float (*output)[BLOCK_SIZE] = ctx->output;
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
output[1][i] += (output[2][i] - output[4][i] - output[5][i]);
|
|
output[2][i] += (output[3][i] + output[4][i] + output[5][i]);
|
|
}
|
|
memset(output[3], 0, sizeof(output[3]));
|
|
memset(output[4], 0, sizeof(output[4]));
|
|
memset(output[5], 0, sizeof(output[5]));
|
|
}
|
|
/*********** END DOWNMIX FUNCTIONS ***********/
|
|
|
|
/* Downmix the output.
|
|
* This function downmixes the output when the number of input
|
|
* channels is not equal to the number of output channels requested.
|
|
*/
|
|
static void do_downmix(AC3DecodeContext *ctx)
|
|
{
|
|
int from = ctx->acmod;
|
|
int to = ctx->blkoutput;
|
|
|
|
if (to == AC3_OUTPUT_UNMODIFIED)
|
|
return;
|
|
|
|
switch (from) {
|
|
case AC3_ACMOD_DUALMONO:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
mix_dualmono_to_mono(ctx);
|
|
break;
|
|
case AC3_OUTPUT_STEREO: /* We assume that sum of both mono channels is requested */
|
|
mix_dualmono_to_stereo(ctx);
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_MONO:
|
|
switch (to) {
|
|
case AC3_OUTPUT_STEREO:
|
|
upmix_mono_to_stereo(ctx);
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_STEREO:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
mix_stereo_to_mono(ctx);
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_3F:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
mix_3f_to_mono(ctx);
|
|
break;
|
|
case AC3_OUTPUT_STEREO:
|
|
mix_3f_to_stereo(ctx);
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_2F1R:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
mix_2f_1r_to_mono(ctx);
|
|
break;
|
|
case AC3_OUTPUT_STEREO:
|
|
mix_2f_1r_to_stereo(ctx);
|
|
break;
|
|
case AC3_OUTPUT_DOLBY:
|
|
mix_2f_1r_to_dolby(ctx);
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_3F1R:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
mix_3f_1r_to_mono(ctx);
|
|
break;
|
|
case AC3_OUTPUT_STEREO:
|
|
mix_3f_1r_to_stereo(ctx);
|
|
break;
|
|
case AC3_OUTPUT_DOLBY:
|
|
mix_3f_1r_to_dolby(ctx);
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_2F2R:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
mix_2f_2r_to_mono(ctx);
|
|
break;
|
|
case AC3_OUTPUT_STEREO:
|
|
mix_2f_2r_to_stereo(ctx);
|
|
break;
|
|
case AC3_OUTPUT_DOLBY:
|
|
mix_2f_2r_to_dolby(ctx);
|
|
break;
|
|
}
|
|
break;
|
|
case AC3_ACMOD_3F2R:
|
|
switch (to) {
|
|
case AC3_OUTPUT_MONO:
|
|
mix_3f_2r_to_mono(ctx);
|
|
break;
|
|
case AC3_OUTPUT_STEREO:
|
|
mix_3f_2r_to_stereo(ctx);
|
|
break;
|
|
case AC3_OUTPUT_DOLBY:
|
|
mix_3f_2r_to_dolby(ctx);
|
|
break;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* This function performs the imdct on 256 sample transform
|
|
* coefficients.
|
|
*/
|
|
static void do_imdct_256(AC3DecodeContext *ctx, int chindex)
|
|
{
|
|
int k;
|
|
float x1[128], x2[128];
|
|
float *o_ptr, *d_ptr, *w;
|
|
FFTComplex *ptr1, *ptr2;
|
|
|
|
for (k = 0; k < N / 4; k++) {
|
|
x1[k] = ctx->transform_coeffs[chindex][2 * k];
|
|
x2[k] = ctx->transform_coeffs[chindex][2 * k + 1];
|
|
}
|
|
|
|
ctx->imdct_256.fft.imdct_calc(&ctx->imdct_256, ctx->tmp_output, x1, ctx->tmp_imdct);
|
|
ctx->imdct_256.fft.imdct_calc(&ctx->imdct_256, ctx->tmp_output + 256, x2, ctx->tmp_imdct);
|
|
|
|
o_ptr = ctx->output[chindex];
|
|
d_ptr = ctx->delay[chindex];
|
|
ptr1 = (FFTComplex *)ctx->tmp_output;
|
|
ptr2 = (FFTComplex *)ctx->tmp_output + 256;
|
|
w = ctx->window;
|
|
|
|
for (k = 0; k < N / 8; k++)
|
|
{
|
|
o_ptr[2 * k] = -ptr1[k].im * w[2 * k] + d_ptr[2 * k] + 384.0;
|
|
o_ptr[2 * k + 1] = ptr1[N / 8 - k - 1].re * w[2 * k + 1] + 384.0;
|
|
o_ptr[N / 4 + 2 * k] = -ptr1[k].re * w[N / 4 + 2 * k] + d_ptr[N / 4 + 2 * k] + 384.0;
|
|
o_ptr[N / 4 + 2 * k + 1] = ptr1[N / 8 - k - 1].im * w[N / 4 + 2 * k + 1] + d_ptr[N / 4 + 2 * k + 1] + 384.0;
|
|
d_ptr[2 * k] = ptr2[k].re * w[k / 2 - 2 * k - 1];
|
|
d_ptr[2 * k + 1] = -ptr2[N / 8 - k - 1].im * w[N / 2 - 2 * k - 2];
|
|
d_ptr[N / 4 + 2 * k] = ptr2[k].im * w[N / 4 - 2 * k - 1];
|
|
d_ptr[N / 4 + 2 * k + 1] = -ptr2[N / 8 - k - 1].re * w[N / 4 - 2 * k - 2];
|
|
}
|
|
}
|
|
|
|
/* This function performs the imdct on 512 sample transform
|
|
* coefficients.
|
|
*/
|
|
static void do_imdct_512(AC3DecodeContext *ctx, int chindex)
|
|
{
|
|
float *ptr;
|
|
|
|
ctx->imdct_512.fft.imdct_calc(&ctx->imdct_512, ctx->tmp_output,
|
|
ctx->transform_coeffs[chindex], ctx->tmp_imdct);
|
|
ptr = ctx->output[chindex];
|
|
ctx->dsp.vector_fmul_add_add(ptr, ctx->tmp_output, ctx->window, ctx->delay[chindex], 384, BLOCK_SIZE, 1);
|
|
ptr = ctx->delay[chindex];
|
|
ctx->dsp.vector_fmul_reverse(ptr, ctx->tmp_output + 256, ctx->window, BLOCK_SIZE);
|
|
}
|
|
|
|
/* IMDCT Transform. */
|
|
static inline void do_imdct(AC3DecodeContext *ctx)
|
|
{
|
|
int i;
|
|
|
|
if (ctx->blkoutput & AC3_OUTPUT_LFEON) {
|
|
do_imdct_512(ctx, 0);
|
|
}
|
|
for (i = 0; i < ctx->nfchans; i++) {
|
|
if ((ctx->blksw >> i) & 1)
|
|
do_imdct_256(ctx, i + 1);
|
|
else
|
|
do_imdct_512(ctx, i + 1);
|
|
}
|
|
}
|
|
|
|
/* Parse the audio block from ac3 bitstream.
|
|
* This function extract the audio block from the ac3 bitstream
|
|
* and produces the output for the block. This function must
|
|
* be called for each of the six audio block in the ac3 bitstream.
|
|
*/
|
|
static int ac3_parse_audio_block(AC3DecodeContext * ctx)
|
|
{
|
|
int nfchans = ctx->nfchans;
|
|
int acmod = ctx->acmod;
|
|
int i, bnd, rbnd, seg, grpsize;
|
|
GetBitContext *gb = &ctx->gb;
|
|
int bit_alloc_flags = 0;
|
|
uint8_t *dexps;
|
|
int mstrcplco, cplcoexp, cplcomant;
|
|
int dynrng, chbwcod, ngrps, cplabsexp, skipl;
|
|
|
|
ctx->blksw = 0;
|
|
for (i = 0; i < nfchans; i++) /*block switch flag */
|
|
ctx->blksw |= get_bits1(gb) << i;
|
|
|
|
ctx->dithflag = 0;
|
|
for (i = 0; i < nfchans; i++) /* dithering flag */
|
|
ctx->dithflag |= get_bits1(gb) << i;
|
|
|
|
if (get_bits1(gb)) { /* dynamic range */
|
|
dynrng = get_sbits(gb, 8);
|
|
ctx->dynrng = ((((dynrng & 0x1f) | 0x20) << 13) * scale_factors[3 - (dynrng >> 5)]);
|
|
}
|
|
|
|
if (acmod == 0x00 && get_bits1(gb)) { /* dynamic range 1+1 mode */
|
|
dynrng = get_sbits(gb, 8);
|
|
ctx->dynrng2 = ((((dynrng & 0x1f) | 0x20) << 13) * scale_factors[3 - (dynrng >> 5)]);
|
|
}
|
|
|
|
get_downmix_coeffs(ctx);
|
|
|
|
if (get_bits1(gb)) { /* coupling strategy */
|
|
ctx->cplinu = get_bits1(gb);
|
|
ctx->cplbndstrc = 0;
|
|
ctx->chincpl = 0;
|
|
if (ctx->cplinu) { /* coupling in use */
|
|
for (i = 0; i < nfchans; i++)
|
|
ctx->chincpl |= get_bits1(gb) << i;
|
|
|
|
if (acmod == 0x02)
|
|
ctx->phsflginu = get_bits1(gb); //phase flag in use
|
|
|
|
ctx->cplbegf = get_bits(gb, 4);
|
|
ctx->cplendf = get_bits(gb, 4);
|
|
|
|
if (3 + ctx->cplendf - ctx->cplbegf < 0) {
|
|
av_log(NULL, AV_LOG_ERROR, "cplendf = %d < cplbegf = %d\n", ctx->cplendf, ctx->cplbegf);
|
|
return -1;
|
|
}
|
|
|
|
ctx->ncplbnd = ctx->ncplsubnd = 3 + ctx->cplendf - ctx->cplbegf;
|
|
ctx->cplstrtmant = ctx->cplbegf * 12 + 37;
|
|
ctx->cplendmant = ctx->cplendf * 12 + 73;
|
|
for (i = 0; i < ctx->ncplsubnd - 1; i++) /* coupling band structure */
|
|
if (get_bits1(gb)) {
|
|
ctx->cplbndstrc |= 1 << i;
|
|
ctx->ncplbnd--;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (ctx->cplinu) {
|
|
ctx->cplcoe = 0;
|
|
|
|
for (i = 0; i < nfchans; i++)
|
|
if ((ctx->chincpl) >> i & 1)
|
|
if (get_bits1(gb)) { /* coupling co-ordinates */
|
|
ctx->cplcoe |= 1 << i;
|
|
mstrcplco = 3 * get_bits(gb, 2);
|
|
for (bnd = 0; bnd < ctx->ncplbnd; bnd++) {
|
|
cplcoexp = get_bits(gb, 4);
|
|
cplcomant = get_bits(gb, 4);
|
|
if (cplcoexp == 15)
|
|
cplcomant <<= 14;
|
|
else
|
|
cplcomant = (cplcomant | 0x10) << 13;
|
|
ctx->cplco[i][bnd] = cplcomant * scale_factors[cplcoexp + mstrcplco];
|
|
}
|
|
}
|
|
|
|
if (acmod == 0x02 && ctx->phsflginu && (ctx->cplcoe & 1 || ctx->cplcoe & 2))
|
|
for (bnd = 0; bnd < ctx->ncplbnd; bnd++)
|
|
if (get_bits1(gb))
|
|
ctx->cplco[1][bnd] = -ctx->cplco[1][bnd];
|
|
}
|
|
|
|
if (acmod == 0x02) {/* rematrixing */
|
|
ctx->rematstr = get_bits1(gb);
|
|
if (ctx->rematstr) {
|
|
ctx->rematflg = 0;
|
|
|
|
if (!(ctx->cplinu) || ctx->cplbegf > 2)
|
|
for (rbnd = 0; rbnd < 4; rbnd++)
|
|
ctx->rematflg |= get_bits1(gb) << rbnd;
|
|
if (ctx->cplbegf > 0 && ctx->cplbegf <= 2 && ctx->cplinu)
|
|
for (rbnd = 0; rbnd < 3; rbnd++)
|
|
ctx->rematflg |= get_bits1(gb) << rbnd;
|
|
if (ctx->cplbegf == 0 && ctx->cplinu)
|
|
for (rbnd = 0; rbnd < 2; rbnd++)
|
|
ctx->rematflg |= get_bits1(gb) << rbnd;
|
|
}
|
|
}
|
|
|
|
ctx->cplexpstr = EXP_REUSE;
|
|
ctx->lfeexpstr = EXP_REUSE;
|
|
if (ctx->cplinu) /* coupling exponent strategy */
|
|
ctx->cplexpstr = get_bits(gb, 2);
|
|
for (i = 0; i < nfchans; i++) /* channel exponent strategy */
|
|
ctx->chexpstr[i] = get_bits(gb, 2);
|
|
if (ctx->lfeon) /* lfe exponent strategy */
|
|
ctx->lfeexpstr = get_bits1(gb);
|
|
|
|
for (i = 0; i < nfchans; i++) /* channel bandwidth code */
|
|
if (ctx->chexpstr[i] != EXP_REUSE) {
|
|
if ((ctx->chincpl >> i) & 1)
|
|
ctx->endmant[i] = ctx->cplstrtmant;
|
|
else {
|
|
chbwcod = get_bits(gb, 6);
|
|
if (chbwcod > 60) {
|
|
av_log(NULL, AV_LOG_ERROR, "chbwcod = %d > 60", chbwcod);
|
|
return -1;
|
|
}
|
|
ctx->endmant[i] = chbwcod * 3 + 73;
|
|
}
|
|
}
|
|
|
|
if (ctx->cplexpstr != EXP_REUSE) {/* coupling exponents */
|
|
bit_alloc_flags = 64;
|
|
cplabsexp = get_bits(gb, 4) << 1;
|
|
ngrps = (ctx->cplendmant - ctx->cplstrtmant) / (3 << (ctx->cplexpstr - 1));
|
|
if (decode_exponents(gb, ctx->cplexpstr, ngrps, cplabsexp, ctx->dcplexps + ctx->cplstrtmant)) {
|
|
av_log(NULL, AV_LOG_ERROR, "error decoding coupling exponents\n");
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < nfchans; i++) /* fbw channel exponents */
|
|
if (ctx->chexpstr[i] != EXP_REUSE) {
|
|
bit_alloc_flags |= 1 << i;
|
|
grpsize = 3 << (ctx->chexpstr[i] - 1);
|
|
ngrps = (ctx->endmant[i] + grpsize - 4) / grpsize;
|
|
dexps = ctx->dexps[i];
|
|
dexps[0] = get_bits(gb, 4);
|
|
if (decode_exponents(gb, ctx->chexpstr[i], ngrps, dexps[0], dexps + 1)) {
|
|
av_log(NULL, AV_LOG_ERROR, "error decoding channel %d exponents\n", i);
|
|
return -1;
|
|
}
|
|
skip_bits(gb, 2); /* skip gainrng */
|
|
}
|
|
|
|
if (ctx->lfeexpstr != EXP_REUSE) { /* lfe exponents */
|
|
bit_alloc_flags |= 32;
|
|
ctx->dlfeexps[0] = get_bits(gb, 4);
|
|
if (decode_exponents(gb, ctx->lfeexpstr, 2, ctx->dlfeexps[0], ctx->dlfeexps + 1)) {
|
|
av_log(NULL, AV_LOG_ERROR, "error decoding lfe exponents\n");
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
if (get_bits1(gb)) { /* bit allocation information */
|
|
bit_alloc_flags = 127;
|
|
ctx->sdcycod = get_bits(gb, 2);
|
|
ctx->fdcycod = get_bits(gb, 2);
|
|
ctx->sgaincod = get_bits(gb, 2);
|
|
ctx->dbpbcod = get_bits(gb, 2);
|
|
ctx->floorcod = get_bits(gb, 3);
|
|
}
|
|
|
|
if (get_bits1(gb)) { /* snroffset */
|
|
bit_alloc_flags = 127;
|
|
ctx->csnroffst = get_bits(gb, 6);
|
|
if (ctx->cplinu) { /* coupling fine snr offset and fast gain code */
|
|
ctx->cplfsnroffst = get_bits(gb, 4);
|
|
ctx->cplfgaincod = get_bits(gb, 3);
|
|
}
|
|
for (i = 0; i < nfchans; i++) { /* channel fine snr offset and fast gain code */
|
|
ctx->fsnroffst[i] = get_bits(gb, 4);
|
|
ctx->fgaincod[i] = get_bits(gb, 3);
|
|
}
|
|
if (ctx->lfeon) { /* lfe fine snr offset and fast gain code */
|
|
ctx->lfefsnroffst = get_bits(gb, 4);
|
|
ctx->lfefgaincod = get_bits(gb, 3);
|
|
}
|
|
}
|
|
|
|
if (ctx->cplinu && get_bits1(gb)) { /* coupling leak information */
|
|
bit_alloc_flags |= 64;
|
|
ctx->cplfleak = get_bits(gb, 3);
|
|
ctx->cplsleak = get_bits(gb, 3);
|
|
}
|
|
|
|
if (get_bits1(gb)) { /* delta bit allocation information */
|
|
bit_alloc_flags = 127;
|
|
|
|
if (ctx->cplinu) {
|
|
ctx->cpldeltbae = get_bits(gb, 2);
|
|
if (ctx->cpldeltbae == DBA_RESERVED) {
|
|
av_log(NULL, AV_LOG_ERROR, "coupling delta bit allocation strategy reserved\n");
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < nfchans; i++) {
|
|
ctx->deltbae[i] = get_bits(gb, 2);
|
|
if (ctx->deltbae[i] == DBA_RESERVED) {
|
|
av_log(NULL, AV_LOG_ERROR, "delta bit allocation strategy reserved\n");
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
if (ctx->cplinu)
|
|
if (ctx->cpldeltbae == DBA_NEW) { /*coupling delta offset, len and bit allocation */
|
|
ctx->cpldeltnseg = get_bits(gb, 3);
|
|
for (seg = 0; seg <= ctx->cpldeltnseg; seg++) {
|
|
ctx->cpldeltoffst[seg] = get_bits(gb, 5);
|
|
ctx->cpldeltlen[seg] = get_bits(gb, 4);
|
|
ctx->cpldeltba[seg] = get_bits(gb, 3);
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < nfchans; i++)
|
|
if (ctx->deltbae[i] == DBA_NEW) {/*channel delta offset, len and bit allocation */
|
|
ctx->deltnseg[i] = get_bits(gb, 3);
|
|
for (seg = 0; seg <= ctx->deltnseg[i]; seg++) {
|
|
ctx->deltoffst[i][seg] = get_bits(gb, 5);
|
|
ctx->deltlen[i][seg] = get_bits(gb, 4);
|
|
ctx->deltba[i][seg] = get_bits(gb, 3);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (bit_alloc_flags) {
|
|
if (is_snr_offsets_zero(ctx)) {
|
|
memset(ctx->cplbap, 0, sizeof (ctx->cplbap));
|
|
memset(ctx->lfebap, 0, sizeof (ctx->lfebap));
|
|
for (i = 0; i < nfchans; i++)
|
|
memset(ctx->bap[i], 0, sizeof(ctx->bap[i]));
|
|
} else {
|
|
if (ctx->chincpl && (bit_alloc_flags & 64))
|
|
do_bit_allocation(ctx, 5);
|
|
for (i = 0; i < nfchans; i++)
|
|
if ((bit_alloc_flags >> i) & 1)
|
|
do_bit_allocation(ctx, i);
|
|
if (ctx->lfeon && (bit_alloc_flags & 32))
|
|
do_bit_allocation(ctx, 6);
|
|
}
|
|
}
|
|
|
|
if (get_bits1(gb)) { /* unused dummy data */
|
|
skipl = get_bits(gb, 9);
|
|
while(skipl--)
|
|
skip_bits(gb, 8);
|
|
}
|
|
/* unpack the transform coefficients
|
|
* * this also uncouples channels if coupling is in use.
|
|
*/
|
|
if (get_transform_coeffs(ctx)) {
|
|
av_log(NULL, AV_LOG_ERROR, "Error in routine get_transform_coeffs\n");
|
|
return -1;
|
|
}
|
|
|
|
/* recover coefficients if rematrixing is in use */
|
|
if (ctx->rematflg)
|
|
do_rematrixing(ctx);
|
|
|
|
do_downmix(ctx);
|
|
|
|
do_imdct(ctx);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int16_t convert(int32_t i)
|
|
{
|
|
if (i > 0x43c07fff)
|
|
return 32767;
|
|
else if (i <= 0x43bf8000)
|
|
return -32768;
|
|
else
|
|
return (i - 0x43c00000);
|
|
}
|
|
|
|
/* Decode ac3 frame.
|
|
*
|
|
* @param avctx Pointer to AVCodecContext
|
|
* @param data Pointer to pcm smaples
|
|
* @param data_size Set to number of pcm samples produced by decoding
|
|
* @param buf Data to be decoded
|
|
* @param buf_size Size of the buffer
|
|
*/
|
|
static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size, uint8_t *buf, int buf_size)
|
|
{
|
|
AC3DecodeContext *ctx = (AC3DecodeContext *)avctx->priv_data;
|
|
int frame_start;
|
|
int16_t *out_samples = (int16_t *)data;
|
|
int i, j, k, start;
|
|
int32_t *int_ptr[6];
|
|
|
|
for (i = 0; i < 6; i++)
|
|
int_ptr[i] = (int32_t *)(&ctx->output[i]);
|
|
|
|
//Synchronize the frame.
|
|
frame_start = ac3_synchronize(buf, buf_size);
|
|
if (frame_start == -1) {
|
|
av_log(avctx, AV_LOG_ERROR, "frame is not synchronized\n");
|
|
*data_size = 0;
|
|
return buf_size;
|
|
}
|
|
|
|
//Initialize the GetBitContext with the start of valid AC3 Frame.
|
|
init_get_bits(&(ctx->gb), buf + frame_start, (buf_size - frame_start) * 8);
|
|
|
|
//Parse the syncinfo.
|
|
//If 'fscod' or 'bsid' is not valid the decoder shall mute as per the standard.
|
|
if (!ac3_parse_sync_info(ctx)) {
|
|
av_log(avctx, AV_LOG_ERROR, "\n");
|
|
*data_size = 0;
|
|
return buf_size;
|
|
}
|
|
|
|
//Parse the BSI.
|
|
//If 'bsid' is not valid decoder shall not decode the audio as per the standard.
|
|
ac3_parse_bsi(ctx);
|
|
|
|
avctx->sample_rate = ctx->sampling_rate;
|
|
avctx->bit_rate = ctx->bit_rate;
|
|
|
|
if (avctx->channels == 0) {
|
|
ctx->blkoutput |= AC3_OUTPUT_UNMODIFIED;
|
|
if (ctx->lfeon)
|
|
ctx->blkoutput |= AC3_OUTPUT_LFEON;
|
|
avctx->channels = ctx->nfchans + ctx->lfeon;
|
|
}
|
|
else if (avctx->channels == 1)
|
|
ctx->blkoutput |= AC3_OUTPUT_MONO;
|
|
else if (avctx->channels == 2) {
|
|
if (ctx->dsurmod == 0x02)
|
|
ctx->blkoutput |= AC3_OUTPUT_DOLBY;
|
|
else
|
|
ctx->blkoutput |= AC3_OUTPUT_STEREO;
|
|
}
|
|
else {
|
|
if (avctx->channels < (ctx->nfchans + ctx->lfeon))
|
|
av_log(avctx, AV_LOG_INFO, "ac3_decoder: AC3 Source Channels Are Less Then Specified %d: Output to %d Channels\n",avctx->channels, ctx->nfchans + ctx->lfeon);
|
|
ctx->blkoutput |= AC3_OUTPUT_UNMODIFIED;
|
|
if (ctx->lfeon)
|
|
ctx->blkoutput |= AC3_OUTPUT_LFEON;
|
|
avctx->channels = ctx->nfchans + ctx->lfeon;
|
|
}
|
|
|
|
//av_log(avctx, AV_LOG_INFO, "channels = %d \t bit rate = %d \t sampling rate = %d \n", avctx->channels, avctx->bit_rate * 1000, avctx->sample_rate);
|
|
|
|
//Parse the Audio Blocks.
|
|
for (i = 0; i < NB_BLOCKS; i++) {
|
|
if (ac3_parse_audio_block(ctx)) {
|
|
av_log(avctx, AV_LOG_ERROR, "error parsing the audio block\n");
|
|
*data_size = 0;
|
|
return ctx->frame_size;
|
|
}
|
|
start = (ctx->blkoutput & AC3_OUTPUT_LFEON) ? 0 : 1;
|
|
for (k = 0; k < BLOCK_SIZE; k++)
|
|
for (j = start; j <= avctx->channels; j++)
|
|
*(out_samples++) = convert(int_ptr[j][k]);
|
|
}
|
|
*data_size = NB_BLOCKS * BLOCK_SIZE * avctx->channels * sizeof (int16_t);
|
|
return ctx->frame_size;
|
|
}
|
|
|
|
/* Uninitialize ac3 decoder.
|
|
*/
|
|
static int ac3_decode_end(AVCodecContext *avctx)
|
|
{
|
|
AC3DecodeContext *ctx = (AC3DecodeContext *)avctx->priv_data;
|
|
ff_mdct_end(&ctx->imdct_512);
|
|
ff_mdct_end(&ctx->imdct_256);
|
|
|
|
return 0;
|
|
}
|
|
|
|
AVCodec lgpl_ac3_decoder = {
|
|
.name = "ac3",
|
|
.type = CODEC_TYPE_AUDIO,
|
|
.id = CODEC_ID_AC3,
|
|
.priv_data_size = sizeof (AC3DecodeContext),
|
|
.init = ac3_decode_init,
|
|
.close = ac3_decode_end,
|
|
.decode = ac3_decode_frame,
|
|
};
|
|
|