forked from FFmpeg/FFmpeg
/
atrac3plus.c
1716 lines (1526 loc) · 65.5 KB
/
atrac3plus.c
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/*
* ATRAC3+ compatible decoder
*
* Copyright (c) 2010-2013 Maxim Poliakovski
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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
*/
/**
* @file
* Bitstream parser for ATRAC3+ decoder.
*/
#include "libavutil/avassert.h"
#include "avcodec.h"
#include "get_bits.h"
#include "atrac3plus.h"
#include "atrac3plus_data.h"
static VLCElem tables_data[154276];
static VLC wl_vlc_tabs[4];
static VLC sf_vlc_tabs[8];
static VLC ct_vlc_tabs[4];
static VLC spec_vlc_tabs[112];
static VLC gain_vlc_tabs[11];
static VLC tone_vlc_tabs[7];
/**
* Generate canonical VLC table from given descriptor.
*
* @param[in] cb ptr to codebook descriptor
* @param[in,out] xlat ptr to ptr to translation table
* @param[in,out] tab_offset starting offset to the generated vlc table
* @param[out] out_vlc ptr to vlc table to be generated
*/
static av_cold void build_canonical_huff(const uint8_t *cb, const uint8_t **xlat,
int *tab_offset, VLC *out_vlc)
{
int i, max_len;
uint8_t bits[256];
int index = 0;
for (int b = 1; b <= 12; b++) {
for (i = *cb++; i > 0; i--) {
av_assert0(index < 256);
bits[index] = b;
index++;
}
}
max_len = bits[index - 1];
out_vlc->table = &tables_data[*tab_offset];
out_vlc->table_allocated = 1 << max_len;
ff_vlc_init_from_lengths(out_vlc, max_len, index, bits, 1,
*xlat, 1, 1, 0, VLC_INIT_USE_STATIC, NULL);
*tab_offset += 1 << max_len;
*xlat += index;
}
av_cold void ff_atrac3p_init_vlcs(void)
{
int i, tab_offset = 0;
const uint8_t *xlats;
xlats = atrac3p_wl_ct_xlats;
for (int i = 0; i < 4; i++) {
build_canonical_huff(atrac3p_wl_cbs[i], &xlats,
&tab_offset, &wl_vlc_tabs[i]);
build_canonical_huff(atrac3p_ct_cbs[i], &xlats,
&tab_offset, &ct_vlc_tabs[i]);
}
xlats = atrac3p_sf_xlats;
for (int i = 0; i < 8; i++)
build_canonical_huff(atrac3p_sf_cbs[i], &xlats,
&tab_offset, &sf_vlc_tabs[i]);
/* build huffman tables for spectrum decoding */
xlats = atrac3p_spectra_xlats;
for (i = 0; i < 112; i++) {
if (atrac3p_spectra_cbs[i][0] >= 0)
build_canonical_huff(atrac3p_spectra_cbs[i],
&xlats, &tab_offset, &spec_vlc_tabs[i]);
else /* Reuse already initialized VLC table */
spec_vlc_tabs[i] = spec_vlc_tabs[-atrac3p_spectra_cbs[i][0]];
}
/* build huffman tables for gain data decoding */
xlats = atrac3p_gain_xlats;
for (i = 0; i < 11; i++)
build_canonical_huff(atrac3p_gain_cbs[i], &xlats,
&tab_offset, &gain_vlc_tabs[i]);
/* build huffman tables for tone decoding */
xlats = atrac3p_tone_xlats;
for (i = 0; i < 7; i++)
build_canonical_huff(atrac3p_tone_cbs[i], &xlats,
&tab_offset, &tone_vlc_tabs[i]);
}
/**
* Decode number of coded quantization units.
*
* @param[in] gb the GetBit context
* @param[in,out] chan ptr to the channel parameters
* @param[in,out] ctx ptr to the channel unit context
* @param[in] avctx ptr to the AVCodecContext
* @return result code: 0 = OK, otherwise - error code
*/
static int num_coded_units(GetBitContext *gb, Atrac3pChanParams *chan,
Atrac3pChanUnitCtx *ctx, AVCodecContext *avctx)
{
chan->fill_mode = get_bits(gb, 2);
if (!chan->fill_mode) {
chan->num_coded_vals = ctx->num_quant_units;
} else {
chan->num_coded_vals = get_bits(gb, 5);
if (chan->num_coded_vals > ctx->num_quant_units) {
av_log(avctx, AV_LOG_ERROR,
"Invalid number of transmitted units!\n");
return AVERROR_INVALIDDATA;
}
if (chan->fill_mode == 3)
chan->split_point = get_bits(gb, 2) + (chan->ch_num << 1) + 1;
}
return 0;
}
/**
* Add weighting coefficients to the decoded word-length information.
*
* @param[in,out] ctx ptr to the channel unit context
* @param[in,out] chan ptr to the channel parameters
* @param[in] wtab_idx index of the table of weights
* @param[in] avctx ptr to the AVCodecContext
* @return result code: 0 = OK, otherwise - error code
*/
static int add_wordlen_weights(Atrac3pChanUnitCtx *ctx,
Atrac3pChanParams *chan, int wtab_idx,
AVCodecContext *avctx)
{
int i;
const int8_t *weights_tab =
&atrac3p_wl_weights[chan->ch_num * 3 + wtab_idx - 1][0];
for (i = 0; i < ctx->num_quant_units; i++) {
chan->qu_wordlen[i] += weights_tab[i];
if (chan->qu_wordlen[i] < 0 || chan->qu_wordlen[i] > 7) {
av_log(avctx, AV_LOG_ERROR,
"WL index out of range: pos=%d, val=%d!\n",
i, chan->qu_wordlen[i]);
return AVERROR_INVALIDDATA;
}
}
return 0;
}
/**
* Subtract weighting coefficients from decoded scalefactors.
*
* @param[in,out] ctx ptr to the channel unit context
* @param[in,out] chan ptr to the channel parameters
* @param[in] wtab_idx index of table of weights
* @param[in] avctx ptr to the AVCodecContext
* @return result code: 0 = OK, otherwise - error code
*/
static int subtract_sf_weights(Atrac3pChanUnitCtx *ctx,
Atrac3pChanParams *chan, int wtab_idx,
AVCodecContext *avctx)
{
int i;
const int8_t *weights_tab = &atrac3p_sf_weights[wtab_idx - 1][0];
for (i = 0; i < ctx->used_quant_units; i++) {
chan->qu_sf_idx[i] -= weights_tab[i];
if (chan->qu_sf_idx[i] < 0 || chan->qu_sf_idx[i] > 63) {
av_log(avctx, AV_LOG_ERROR,
"SF index out of range: pos=%d, val=%d!\n",
i, chan->qu_sf_idx[i]);
return AVERROR_INVALIDDATA;
}
}
return 0;
}
/**
* Unpack vector quantization tables.
*
* @param[in] start_val start value for the unpacked table
* @param[in] shape_vec ptr to table to unpack
* @param[out] dst ptr to output array
* @param[in] num_values number of values to unpack
*/
static inline void unpack_vq_shape(int start_val, const int8_t *shape_vec,
int *dst, int num_values)
{
int i;
if (num_values) {
dst[0] = dst[1] = dst[2] = start_val;
for (i = 3; i < num_values; i++)
dst[i] = start_val - shape_vec[atrac3p_qu_num_to_seg[i] - 1];
}
}
#define UNPACK_SF_VQ_SHAPE(gb, dst, num_vals) \
start_val = get_bits((gb), 6); \
unpack_vq_shape(start_val, &atrac3p_sf_shapes[get_bits((gb), 6)][0], \
(dst), (num_vals))
/**
* Decode word length for each quantization unit of a channel.
*
* @param[in] gb the GetBit context
* @param[in,out] ctx ptr to the channel unit context
* @param[in] ch_num channel to process
* @param[in] avctx ptr to the AVCodecContext
* @return result code: 0 = OK, otherwise - error code
*/
static int decode_channel_wordlen(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
int ch_num, AVCodecContext *avctx)
{
int i, weight_idx = 0, delta, diff, pos, delta_bits, min_val, flag,
ret, start_val;
VLC *vlc_tab;
Atrac3pChanParams *chan = &ctx->channels[ch_num];
Atrac3pChanParams *ref_chan = &ctx->channels[0];
chan->fill_mode = 0;
switch (get_bits(gb, 2)) { /* switch according to coding mode */
case 0: /* coded using constant number of bits */
for (i = 0; i < ctx->num_quant_units; i++)
chan->qu_wordlen[i] = get_bits(gb, 3);
break;
case 1:
if (ch_num) {
if ((ret = num_coded_units(gb, chan, ctx, avctx)) < 0)
return ret;
if (chan->num_coded_vals) {
vlc_tab = &wl_vlc_tabs[get_bits(gb, 2)];
for (i = 0; i < chan->num_coded_vals; i++) {
delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
chan->qu_wordlen[i] = (ref_chan->qu_wordlen[i] + delta) & 7;
}
}
} else {
weight_idx = get_bits(gb, 2);
if ((ret = num_coded_units(gb, chan, ctx, avctx)) < 0)
return ret;
if (chan->num_coded_vals) {
pos = get_bits(gb, 5);
if (pos > chan->num_coded_vals) {
av_log(avctx, AV_LOG_ERROR,
"WL mode 1: invalid position!\n");
return AVERROR_INVALIDDATA;
}
delta_bits = get_bits(gb, 2);
min_val = get_bits(gb, 3);
for (i = 0; i < pos; i++)
chan->qu_wordlen[i] = get_bits(gb, 3);
for (i = pos; i < chan->num_coded_vals; i++)
chan->qu_wordlen[i] = (min_val + get_bitsz(gb, delta_bits)) & 7;
}
}
break;
case 2:
if ((ret = num_coded_units(gb, chan, ctx, avctx)) < 0)
return ret;
if (ch_num && chan->num_coded_vals) {
vlc_tab = &wl_vlc_tabs[get_bits(gb, 2)];
delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
chan->qu_wordlen[0] = (ref_chan->qu_wordlen[0] + delta) & 7;
for (i = 1; i < chan->num_coded_vals; i++) {
diff = ref_chan->qu_wordlen[i] - ref_chan->qu_wordlen[i - 1];
delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
chan->qu_wordlen[i] = (chan->qu_wordlen[i - 1] + diff + delta) & 7;
}
} else if (chan->num_coded_vals) {
flag = get_bits(gb, 1);
vlc_tab = &wl_vlc_tabs[get_bits(gb, 1)];
start_val = get_bits(gb, 3);
unpack_vq_shape(start_val,
&atrac3p_wl_shapes[start_val][get_bits(gb, 4)][0],
chan->qu_wordlen, chan->num_coded_vals);
if (!flag) {
for (i = 0; i < chan->num_coded_vals; i++) {
delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
chan->qu_wordlen[i] = (chan->qu_wordlen[i] + delta) & 7;
}
} else {
for (i = 0; i < (chan->num_coded_vals & - 2); i += 2)
if (!get_bits1(gb)) {
chan->qu_wordlen[i] = (chan->qu_wordlen[i] +
get_vlc2(gb, vlc_tab->table,
vlc_tab->bits, 1)) & 7;
chan->qu_wordlen[i + 1] = (chan->qu_wordlen[i + 1] +
get_vlc2(gb, vlc_tab->table,
vlc_tab->bits, 1)) & 7;
}
if (chan->num_coded_vals & 1)
chan->qu_wordlen[i] = (chan->qu_wordlen[i] +
get_vlc2(gb, vlc_tab->table,
vlc_tab->bits, 1)) & 7;
}
}
break;
case 3:
weight_idx = get_bits(gb, 2);
if ((ret = num_coded_units(gb, chan, ctx, avctx)) < 0)
return ret;
if (chan->num_coded_vals) {
vlc_tab = &wl_vlc_tabs[get_bits(gb, 2)];
/* first coefficient is coded directly */
chan->qu_wordlen[0] = get_bits(gb, 3);
for (i = 1; i < chan->num_coded_vals; i++) {
delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
chan->qu_wordlen[i] = (chan->qu_wordlen[i - 1] + delta) & 7;
}
}
break;
}
if (chan->fill_mode == 2) {
for (i = chan->num_coded_vals; i < ctx->num_quant_units; i++)
chan->qu_wordlen[i] = ch_num ? get_bits1(gb) : 1;
} else if (chan->fill_mode == 3) {
pos = ch_num ? chan->num_coded_vals + chan->split_point
: ctx->num_quant_units - chan->split_point;
if (pos > FF_ARRAY_ELEMS(chan->qu_wordlen)) {
av_log(avctx, AV_LOG_ERROR, "Split point beyond array\n");
pos = FF_ARRAY_ELEMS(chan->qu_wordlen);
}
for (i = chan->num_coded_vals; i < pos; i++)
chan->qu_wordlen[i] = 1;
}
if (weight_idx)
return add_wordlen_weights(ctx, chan, weight_idx, avctx);
return 0;
}
/**
* Decode scale factor indexes for each quant unit of a channel.
*
* @param[in] gb the GetBit context
* @param[in,out] ctx ptr to the channel unit context
* @param[in] ch_num channel to process
* @param[in] avctx ptr to the AVCodecContext
* @return result code: 0 = OK, otherwise - error code
*/
static int decode_channel_sf_idx(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
int ch_num, AVCodecContext *avctx)
{
int i, weight_idx = 0, delta, diff, num_long_vals,
delta_bits, min_val, vlc_sel, start_val;
VLC *vlc_tab;
Atrac3pChanParams *chan = &ctx->channels[ch_num];
Atrac3pChanParams *ref_chan = &ctx->channels[0];
switch (get_bits(gb, 2)) { /* switch according to coding mode */
case 0: /* coded using constant number of bits */
for (i = 0; i < ctx->used_quant_units; i++)
chan->qu_sf_idx[i] = get_bits(gb, 6);
break;
case 1:
if (ch_num) {
vlc_tab = &sf_vlc_tabs[get_bits(gb, 2)];
for (i = 0; i < ctx->used_quant_units; i++) {
delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
chan->qu_sf_idx[i] = (ref_chan->qu_sf_idx[i] + delta) & 0x3F;
}
} else {
weight_idx = get_bits(gb, 2);
if (weight_idx == 3) {
UNPACK_SF_VQ_SHAPE(gb, chan->qu_sf_idx, ctx->used_quant_units);
num_long_vals = get_bits(gb, 5);
delta_bits = get_bits(gb, 2);
min_val = get_bits(gb, 4) - 7;
for (i = 0; i < num_long_vals; i++)
chan->qu_sf_idx[i] = (chan->qu_sf_idx[i] +
get_bits(gb, 4) - 7) & 0x3F;
/* all others are: min_val + delta */
for (i = num_long_vals; i < ctx->used_quant_units; i++)
chan->qu_sf_idx[i] = (chan->qu_sf_idx[i] + min_val +
get_bitsz(gb, delta_bits)) & 0x3F;
} else {
num_long_vals = get_bits(gb, 5);
delta_bits = get_bits(gb, 3);
min_val = get_bits(gb, 6);
if (num_long_vals > ctx->used_quant_units || delta_bits == 7) {
av_log(avctx, AV_LOG_ERROR,
"SF mode 1: invalid parameters!\n");
return AVERROR_INVALIDDATA;
}
/* read full-precision SF indexes */
for (i = 0; i < num_long_vals; i++)
chan->qu_sf_idx[i] = get_bits(gb, 6);
/* all others are: min_val + delta */
for (i = num_long_vals; i < ctx->used_quant_units; i++)
chan->qu_sf_idx[i] = (min_val +
get_bitsz(gb, delta_bits)) & 0x3F;
}
}
break;
case 2:
if (ch_num) {
vlc_tab = &sf_vlc_tabs[get_bits(gb, 2)];
delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
chan->qu_sf_idx[0] = (ref_chan->qu_sf_idx[0] + delta) & 0x3F;
for (i = 1; i < ctx->used_quant_units; i++) {
diff = ref_chan->qu_sf_idx[i] - ref_chan->qu_sf_idx[i - 1];
delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
chan->qu_sf_idx[i] = (chan->qu_sf_idx[i - 1] + diff + delta) & 0x3F;
}
} else {
vlc_tab = &sf_vlc_tabs[get_bits(gb, 2) + 4];
UNPACK_SF_VQ_SHAPE(gb, chan->qu_sf_idx, ctx->used_quant_units);
for (i = 0; i < ctx->used_quant_units; i++) {
delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
chan->qu_sf_idx[i] = (chan->qu_sf_idx[i] +
sign_extend(delta, 4)) & 0x3F;
}
}
break;
case 3:
if (ch_num) {
/* copy coefficients from reference channel */
for (i = 0; i < ctx->used_quant_units; i++)
chan->qu_sf_idx[i] = ref_chan->qu_sf_idx[i];
} else {
weight_idx = get_bits(gb, 2);
vlc_sel = get_bits(gb, 2);
vlc_tab = &sf_vlc_tabs[vlc_sel];
if (weight_idx == 3) {
vlc_tab = &sf_vlc_tabs[vlc_sel + 4];
UNPACK_SF_VQ_SHAPE(gb, chan->qu_sf_idx, ctx->used_quant_units);
diff = (get_bits(gb, 4) + 56) & 0x3F;
chan->qu_sf_idx[0] = (chan->qu_sf_idx[0] + diff) & 0x3F;
for (i = 1; i < ctx->used_quant_units; i++) {
delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
diff = (diff + sign_extend(delta, 4)) & 0x3F;
chan->qu_sf_idx[i] = (diff + chan->qu_sf_idx[i]) & 0x3F;
}
} else {
/* 1st coefficient is coded directly */
chan->qu_sf_idx[0] = get_bits(gb, 6);
for (i = 1; i < ctx->used_quant_units; i++) {
delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
chan->qu_sf_idx[i] = (chan->qu_sf_idx[i - 1] + delta) & 0x3F;
}
}
}
break;
}
if (weight_idx && weight_idx < 3)
return subtract_sf_weights(ctx, chan, weight_idx, avctx);
return 0;
}
/**
* Decode word length information for each channel.
*
* @param[in] gb the GetBit context
* @param[in,out] ctx ptr to the channel unit context
* @param[in] num_channels number of channels to process
* @param[in] avctx ptr to the AVCodecContext
* @return result code: 0 = OK, otherwise - error code
*/
static int decode_quant_wordlen(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
int num_channels, AVCodecContext *avctx)
{
int ch_num, i, ret;
for (ch_num = 0; ch_num < num_channels; ch_num++) {
memset(ctx->channels[ch_num].qu_wordlen, 0,
sizeof(ctx->channels[ch_num].qu_wordlen));
if ((ret = decode_channel_wordlen(gb, ctx, ch_num, avctx)) < 0)
return ret;
}
/* scan for last non-zero coeff in both channels and
* set number of quant units having coded spectrum */
for (i = ctx->num_quant_units - 1; i >= 0; i--)
if (ctx->channels[0].qu_wordlen[i] ||
(num_channels == 2 && ctx->channels[1].qu_wordlen[i]))
break;
ctx->used_quant_units = i + 1;
return 0;
}
/**
* Decode scale factor indexes for each channel.
*
* @param[in] gb the GetBit context
* @param[in,out] ctx ptr to the channel unit context
* @param[in] num_channels number of channels to process
* @param[in] avctx ptr to the AVCodecContext
* @return result code: 0 = OK, otherwise - error code
*/
static int decode_scale_factors(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
int num_channels, AVCodecContext *avctx)
{
int ch_num, ret;
if (!ctx->used_quant_units)
return 0;
for (ch_num = 0; ch_num < num_channels; ch_num++) {
memset(ctx->channels[ch_num].qu_sf_idx, 0,
sizeof(ctx->channels[ch_num].qu_sf_idx));
if ((ret = decode_channel_sf_idx(gb, ctx, ch_num, avctx)) < 0)
return ret;
}
return 0;
}
/**
* Decode number of code table values.
*
* @param[in] gb the GetBit context
* @param[in,out] ctx ptr to the channel unit context
* @param[in] avctx ptr to the AVCodecContext
* @return result code: 0 = OK, otherwise - error code
*/
static int get_num_ct_values(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
AVCodecContext *avctx)
{
int num_coded_vals;
if (get_bits1(gb)) {
num_coded_vals = get_bits(gb, 5);
if (num_coded_vals > ctx->used_quant_units) {
av_log(avctx, AV_LOG_ERROR,
"Invalid number of code table indexes: %d!\n", num_coded_vals);
return AVERROR_INVALIDDATA;
}
return num_coded_vals;
} else
return ctx->used_quant_units;
}
#define DEC_CT_IDX_COMMON(OP) \
num_vals = get_num_ct_values(gb, ctx, avctx); \
if (num_vals < 0) \
return num_vals; \
\
for (i = 0; i < num_vals; i++) { \
if (chan->qu_wordlen[i]) { \
chan->qu_tab_idx[i] = OP; \
} else if (ch_num && ref_chan->qu_wordlen[i]) \
/* get clone master flag */ \
chan->qu_tab_idx[i] = get_bits1(gb); \
}
#define CODING_DIRECT get_bits(gb, num_bits)
#define CODING_VLC get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1)
#define CODING_VLC_DELTA \
(!i) ? CODING_VLC \
: (pred + get_vlc2(gb, delta_vlc->table, \
delta_vlc->bits, 1)) & mask; \
pred = chan->qu_tab_idx[i]
#define CODING_VLC_DIFF \
(ref_chan->qu_tab_idx[i] + \
get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1)) & mask
/**
* Decode code table indexes for each quant unit of a channel.
*
* @param[in] gb the GetBit context
* @param[in,out] ctx ptr to the channel unit context
* @param[in] ch_num channel to process
* @param[in] avctx ptr to the AVCodecContext
* @return result code: 0 = OK, otherwise - error code
*/
static int decode_channel_code_tab(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
int ch_num, AVCodecContext *avctx)
{
int i, num_vals, num_bits, pred;
int mask = ctx->use_full_table ? 7 : 3; /* mask for modular arithmetic */
VLC *vlc_tab, *delta_vlc;
Atrac3pChanParams *chan = &ctx->channels[ch_num];
Atrac3pChanParams *ref_chan = &ctx->channels[0];
chan->table_type = get_bits1(gb);
switch (get_bits(gb, 2)) { /* switch according to coding mode */
case 0: /* directly coded */
num_bits = ctx->use_full_table + 2;
DEC_CT_IDX_COMMON(CODING_DIRECT);
break;
case 1: /* entropy-coded */
vlc_tab = ctx->use_full_table ? &ct_vlc_tabs[1]
: ct_vlc_tabs;
DEC_CT_IDX_COMMON(CODING_VLC);
break;
case 2: /* entropy-coded delta */
if (ctx->use_full_table) {
vlc_tab = &ct_vlc_tabs[1];
delta_vlc = &ct_vlc_tabs[2];
} else {
vlc_tab = ct_vlc_tabs;
delta_vlc = ct_vlc_tabs;
}
pred = 0;
DEC_CT_IDX_COMMON(CODING_VLC_DELTA);
break;
case 3: /* entropy-coded difference to master */
if (ch_num) {
vlc_tab = ctx->use_full_table ? &ct_vlc_tabs[3]
: ct_vlc_tabs;
DEC_CT_IDX_COMMON(CODING_VLC_DIFF);
}
break;
}
return 0;
}
/**
* Decode code table indexes for each channel.
*
* @param[in] gb the GetBit context
* @param[in,out] ctx ptr to the channel unit context
* @param[in] num_channels number of channels to process
* @param[in] avctx ptr to the AVCodecContext
* @return result code: 0 = OK, otherwise - error code
*/
static int decode_code_table_indexes(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
int num_channels, AVCodecContext *avctx)
{
int ch_num, ret;
if (!ctx->used_quant_units)
return 0;
ctx->use_full_table = get_bits1(gb);
for (ch_num = 0; ch_num < num_channels; ch_num++) {
memset(ctx->channels[ch_num].qu_tab_idx, 0,
sizeof(ctx->channels[ch_num].qu_tab_idx));
if ((ret = decode_channel_code_tab(gb, ctx, ch_num, avctx)) < 0)
return ret;
}
return 0;
}
/**
* Decode huffman-coded spectral lines for a given quant unit.
*
* This is a generalized version for all known coding modes.
* Its speed can be improved by creating separate functions for each mode.
*
* @param[in] gb the GetBit context
* @param[in] tab code table telling how to decode spectral lines
* @param[in] vlc_tab ptr to the huffman table associated with the code table
* @param[out] out pointer to buffer where decoded data should be stored
* @param[in] num_specs number of spectral lines to decode
*/
static void decode_qu_spectra(GetBitContext *gb, const Atrac3pSpecCodeTab *tab,
VLC *vlc_tab, int16_t *out, const int num_specs)
{
int i, j, pos, cf;
int group_size = tab->group_size;
int num_coeffs = tab->num_coeffs;
int bits = tab->bits;
int is_signed = tab->is_signed;
unsigned val;
for (pos = 0; pos < num_specs;) {
if (group_size == 1 || get_bits1(gb)) {
for (j = 0; j < group_size; j++) {
val = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
for (i = 0; i < num_coeffs; i++) {
cf = av_mod_uintp2(val, bits);
if (is_signed)
cf = sign_extend(cf, bits);
else if (cf && get_bits1(gb))
cf = -cf;
out[pos++] = cf;
val >>= bits;
}
}
} else /* group skipped */
pos += group_size * num_coeffs;
}
}
/**
* Decode huffman-coded IMDCT spectrum for all channels.
*
* @param[in] gb the GetBit context
* @param[in,out] ctx ptr to the channel unit context
* @param[in] num_channels number of channels to process
* @param[in] avctx ptr to the AVCodecContext
*/
static void decode_spectrum(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
int num_channels, AVCodecContext *avctx)
{
int i, ch_num, qu, wordlen, codetab, tab_index, num_specs;
const Atrac3pSpecCodeTab *tab;
Atrac3pChanParams *chan;
for (ch_num = 0; ch_num < num_channels; ch_num++) {
chan = &ctx->channels[ch_num];
memset(chan->spectrum, 0, sizeof(chan->spectrum));
/* set power compensation level to disabled */
memset(chan->power_levs, ATRAC3P_POWER_COMP_OFF, sizeof(chan->power_levs));
for (qu = 0; qu < ctx->used_quant_units; qu++) {
num_specs = ff_atrac3p_qu_to_spec_pos[qu + 1] -
ff_atrac3p_qu_to_spec_pos[qu];
wordlen = chan->qu_wordlen[qu];
codetab = chan->qu_tab_idx[qu];
if (wordlen) {
if (!ctx->use_full_table)
codetab = atrac3p_ct_restricted_to_full[chan->table_type][wordlen - 1][codetab];
tab_index = (chan->table_type * 8 + codetab) * 7 + wordlen - 1;
tab = &atrac3p_spectra_tabs[tab_index];
decode_qu_spectra(gb, tab, &spec_vlc_tabs[tab_index],
&chan->spectrum[ff_atrac3p_qu_to_spec_pos[qu]],
num_specs);
} else if (ch_num && ctx->channels[0].qu_wordlen[qu] && !codetab) {
/* copy coefficients from master */
memcpy(&chan->spectrum[ff_atrac3p_qu_to_spec_pos[qu]],
&ctx->channels[0].spectrum[ff_atrac3p_qu_to_spec_pos[qu]],
num_specs *
sizeof(chan->spectrum[ff_atrac3p_qu_to_spec_pos[qu]]));
chan->qu_wordlen[qu] = ctx->channels[0].qu_wordlen[qu];
}
}
/* Power compensation levels only present in the bitstream
* if there are more than 2 quant units. The lowest two units
* correspond to the frequencies 0...351 Hz, whose shouldn't
* be affected by the power compensation. */
if (ctx->used_quant_units > 2) {
num_specs = atrac3p_subband_to_num_powgrps[ctx->num_coded_subbands - 1];
for (i = 0; i < num_specs; i++)
chan->power_levs[i] = get_bits(gb, 4);
}
}
}
/**
* Retrieve specified amount of flag bits from the input bitstream.
* The data can be shortened in the case of the following two common conditions:
* if all bits are zero then only one signal bit = 0 will be stored,
* if all bits are ones then two signal bits = 1,0 will be stored.
* Otherwise, all necessary bits will be directly stored
* prefixed by two signal bits = 1,1.
*
* @param[in] gb ptr to the GetBitContext
* @param[out] out where to place decoded flags
* @param[in] num_flags number of flags to process
* @return: 0 = all flag bits are zero, 1 = there is at least one non-zero flag bit
*/
static int get_subband_flags(GetBitContext *gb, uint8_t *out, int num_flags)
{
int i, result;
memset(out, 0, num_flags);
result = get_bits1(gb);
if (result) {
if (get_bits1(gb))
for (i = 0; i < num_flags; i++)
out[i] = get_bits1(gb);
else
memset(out, 1, num_flags);
}
return result;
}
/**
* Decode mdct window shape flags for all channels.
*
* @param[in] gb the GetBit context
* @param[in,out] ctx ptr to the channel unit context
* @param[in] num_channels number of channels to process
*/
static void decode_window_shape(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
int num_channels)
{
int ch_num;
for (ch_num = 0; ch_num < num_channels; ch_num++)
get_subband_flags(gb, ctx->channels[ch_num].wnd_shape,
ctx->num_subbands);
}
/**
* Decode number of gain control points.
*
* @param[in] gb the GetBit context
* @param[in,out] ctx ptr to the channel unit context
* @param[in] ch_num channel to process
* @param[in] coded_subbands number of subbands to process
* @return result code: 0 = OK, otherwise - error code
*/
static int decode_gainc_npoints(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
int ch_num, int coded_subbands)
{
int i, delta, delta_bits, min_val;
Atrac3pChanParams *chan = &ctx->channels[ch_num];
Atrac3pChanParams *ref_chan = &ctx->channels[0];
switch (get_bits(gb, 2)) { /* switch according to coding mode */
case 0: /* fixed-length coding */
for (i = 0; i < coded_subbands; i++)
chan->gain_data[i].num_points = get_bits(gb, 3);
break;
case 1: /* variable-length coding */
for (i = 0; i < coded_subbands; i++)
chan->gain_data[i].num_points =
get_vlc2(gb, gain_vlc_tabs[0].table,
gain_vlc_tabs[0].bits, 1);
break;
case 2:
if (ch_num) { /* VLC modulo delta to master channel */
for (i = 0; i < coded_subbands; i++) {
delta = get_vlc2(gb, gain_vlc_tabs[1].table,
gain_vlc_tabs[1].bits, 1);
chan->gain_data[i].num_points =
(ref_chan->gain_data[i].num_points + delta) & 7;
}
} else { /* VLC modulo delta to previous */
chan->gain_data[0].num_points =
get_vlc2(gb, gain_vlc_tabs[0].table,
gain_vlc_tabs[0].bits, 1);
for (i = 1; i < coded_subbands; i++) {
delta = get_vlc2(gb, gain_vlc_tabs[1].table,
gain_vlc_tabs[1].bits, 1);
chan->gain_data[i].num_points =
(chan->gain_data[i - 1].num_points + delta) & 7;
}
}
break;
case 3:
if (ch_num) { /* copy data from master channel */
for (i = 0; i < coded_subbands; i++)
chan->gain_data[i].num_points =
ref_chan->gain_data[i].num_points;
} else { /* shorter delta to min */
delta_bits = get_bits(gb, 2);
min_val = get_bits(gb, 3);
for (i = 0; i < coded_subbands; i++) {
chan->gain_data[i].num_points = min_val + get_bitsz(gb, delta_bits);
if (chan->gain_data[i].num_points > 7)
return AVERROR_INVALIDDATA;
}
}
}
return 0;
}
/**
* Implements coding mode 3 (slave) for gain compensation levels.
*
* @param[out] dst ptr to the output array
* @param[in] ref ptr to the reference channel
*/
static inline void gainc_level_mode3s(AtracGainInfo *dst, AtracGainInfo *ref)
{
int i;
for (i = 0; i < dst->num_points; i++)
dst->lev_code[i] = (i >= ref->num_points) ? 7 : ref->lev_code[i];
}
/**
* Implements coding mode 1 (master) for gain compensation levels.
*
* @param[in] gb the GetBit context
* @param[in] ctx ptr to the channel unit context
* @param[out] dst ptr to the output array
*/
static inline void gainc_level_mode1m(GetBitContext *gb,
Atrac3pChanUnitCtx *ctx,
AtracGainInfo *dst)
{
int i, delta;
if (dst->num_points > 0)
dst->lev_code[0] = get_vlc2(gb, gain_vlc_tabs[2].table,
gain_vlc_tabs[2].bits, 1);
for (i = 1; i < dst->num_points; i++) {
delta = get_vlc2(gb, gain_vlc_tabs[3].table,
gain_vlc_tabs[3].bits, 1);
dst->lev_code[i] = (dst->lev_code[i - 1] + delta) & 0xF;
}
}
/**
* Decode level code for each gain control point.
*
* @param[in] gb the GetBit context
* @param[in,out] ctx ptr to the channel unit context
* @param[in] ch_num channel to process
* @param[in] coded_subbands number of subbands to process
* @return result code: 0 = OK, otherwise - error code
*/
static int decode_gainc_levels(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
int ch_num, int coded_subbands)
{
int sb, i, delta, delta_bits, min_val, pred;
Atrac3pChanParams *chan = &ctx->channels[ch_num];
Atrac3pChanParams *ref_chan = &ctx->channels[0];
switch (get_bits(gb, 2)) { /* switch according to coding mode */
case 0: /* fixed-length coding */
for (sb = 0; sb < coded_subbands; sb++)
for (i = 0; i < chan->gain_data[sb].num_points; i++)
chan->gain_data[sb].lev_code[i] = get_bits(gb, 4);
break;
case 1:
if (ch_num) { /* VLC modulo delta to master channel */
for (sb = 0; sb < coded_subbands; sb++)
for (i = 0; i < chan->gain_data[sb].num_points; i++) {
delta = get_vlc2(gb, gain_vlc_tabs[5].table,
gain_vlc_tabs[5].bits, 1);
pred = (i >= ref_chan->gain_data[sb].num_points)
? 7 : ref_chan->gain_data[sb].lev_code[i];
chan->gain_data[sb].lev_code[i] = (pred + delta) & 0xF;
}
} else { /* VLC modulo delta to previous */
for (sb = 0; sb < coded_subbands; sb++)