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FFmpeg/libavcodec/mpc7.c
Kostya Shishkov 7d3829a87a Musepack SV8 supports "mono" files (though it still codes them as stereo),
so extend decoder to output only one channel for it.

This fixes issue 2368.

Originally committed as revision 25790 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-11-21 20:42:06 +00:00

303 lines
9.9 KiB
C

/*
* Musepack SV7 decoder
* Copyright (c) 2006 Konstantin Shishkov
*
* 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
* MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
* divided into 32 subbands.
*/
#include "libavutil/lfg.h"
#include "avcodec.h"
#include "get_bits.h"
#include "dsputil.h"
#include "mpegaudio.h"
#include "mpc.h"
#include "mpc7data.h"
#define BANDS 32
#define SAMPLES_PER_BAND 36
#define MPC_FRAME_SIZE (BANDS * SAMPLES_PER_BAND)
static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2];
static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] =
{
0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124,
5636, 6164, 6676, 7224
};
static av_cold int mpc7_decode_init(AVCodecContext * avctx)
{
int i, j;
MPCContext *c = avctx->priv_data;
GetBitContext gb;
uint8_t buf[16];
static int vlc_initialized = 0;
static VLC_TYPE scfi_table[1 << MPC7_SCFI_BITS][2];
static VLC_TYPE dscf_table[1 << MPC7_DSCF_BITS][2];
static VLC_TYPE hdr_table[1 << MPC7_HDR_BITS][2];
static VLC_TYPE quant_tables[7224][2];
if(avctx->extradata_size < 16){
av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
return -1;
}
memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
av_lfg_init(&c->rnd, 0xDEADBEEF);
dsputil_init(&c->dsp, avctx);
c->dsp.bswap_buf((uint32_t*)buf, (const uint32_t*)avctx->extradata, 4);
ff_mpc_init();
init_get_bits(&gb, buf, 128);
c->IS = get_bits1(&gb);
c->MSS = get_bits1(&gb);
c->maxbands = get_bits(&gb, 6);
if(c->maxbands >= BANDS){
av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands);
return -1;
}
skip_bits_long(&gb, 88);
c->gapless = get_bits1(&gb);
c->lastframelen = get_bits(&gb, 11);
av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n",
c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands);
c->frames_to_skip = 0;
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO;
if(vlc_initialized) return 0;
av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
scfi_vlc.table = scfi_table;
scfi_vlc.table_allocated = 1 << MPC7_SCFI_BITS;
if(init_vlc(&scfi_vlc, MPC7_SCFI_BITS, MPC7_SCFI_SIZE,
&mpc7_scfi[1], 2, 1,
&mpc7_scfi[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
av_log(avctx, AV_LOG_ERROR, "Cannot init SCFI VLC\n");
return -1;
}
dscf_vlc.table = dscf_table;
dscf_vlc.table_allocated = 1 << MPC7_DSCF_BITS;
if(init_vlc(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE,
&mpc7_dscf[1], 2, 1,
&mpc7_dscf[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
av_log(avctx, AV_LOG_ERROR, "Cannot init DSCF VLC\n");
return -1;
}
hdr_vlc.table = hdr_table;
hdr_vlc.table_allocated = 1 << MPC7_HDR_BITS;
if(init_vlc(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE,
&mpc7_hdr[1], 2, 1,
&mpc7_hdr[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
av_log(avctx, AV_LOG_ERROR, "Cannot init HDR VLC\n");
return -1;
}
for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){
for(j = 0; j < 2; j++){
quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]];
quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j];
if(init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],
&mpc7_quant_vlc[i][j][1], 4, 2,
&mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC)){
av_log(avctx, AV_LOG_ERROR, "Cannot init QUANT VLC %i,%i\n",i,j);
return -1;
}
}
}
vlc_initialized = 1;
return 0;
}
/**
* Fill samples for given subband
*/
static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)
{
int i, i1, t;
switch(idx){
case -1:
for(i = 0; i < SAMPLES_PER_BAND; i++){
*dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
}
break;
case 1:
i1 = get_bits1(gb);
for(i = 0; i < SAMPLES_PER_BAND/3; i++){
t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);
*dst++ = mpc7_idx30[t];
*dst++ = mpc7_idx31[t];
*dst++ = mpc7_idx32[t];
}
break;
case 2:
i1 = get_bits1(gb);
for(i = 0; i < SAMPLES_PER_BAND/2; i++){
t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);
*dst++ = mpc7_idx50[t];
*dst++ = mpc7_idx51[t];
}
break;
case 3: case 4: case 5: case 6: case 7:
i1 = get_bits1(gb);
for(i = 0; i < SAMPLES_PER_BAND; i++)
*dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];
break;
case 8: case 9: case 10: case 11: case 12:
case 13: case 14: case 15: case 16: case 17:
t = (1 << (idx - 2)) - 1;
for(i = 0; i < SAMPLES_PER_BAND; i++)
*dst++ = get_bits(gb, idx - 1) - t;
break;
default: // case 0 and -2..-17
return;
}
}
static int get_scale_idx(GetBitContext *gb, int ref)
{
int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;
if (t == 8)
return get_bits(gb, 6);
return ref + t;
}
static int mpc7_decode_frame(AVCodecContext * avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
MPCContext *c = avctx->priv_data;
GetBitContext gb;
uint8_t *bits;
int i, ch;
int mb = -1;
Band *bands = c->bands;
int off;
int bits_used, bits_avail;
memset(bands, 0, sizeof(bands));
if(buf_size <= 4){
av_log(avctx, AV_LOG_ERROR, "Too small buffer passed (%i bytes)\n", buf_size);
}
bits = av_malloc(((buf_size - 1) & ~3) + FF_INPUT_BUFFER_PADDING_SIZE);
c->dsp.bswap_buf((uint32_t*)bits, (const uint32_t*)(buf + 4), (buf_size - 4) >> 2);
init_get_bits(&gb, bits, (buf_size - 4)* 8);
skip_bits_long(&gb, buf[0]);
/* read subband indexes */
for(i = 0; i <= c->maxbands; i++){
for(ch = 0; ch < 2; ch++){
int t = 4;
if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;
if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);
else bands[i].res[ch] = bands[i-1].res[ch] + t;
}
if(bands[i].res[0] || bands[i].res[1]){
mb = i;
if(c->MSS) bands[i].msf = get_bits1(&gb);
}
}
/* get scale indexes coding method */
for(i = 0; i <= mb; i++)
for(ch = 0; ch < 2; ch++)
if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);
/* get scale indexes */
for(i = 0; i <= mb; i++){
for(ch = 0; ch < 2; ch++){
if(bands[i].res[ch]){
bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];
bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]);
switch(bands[i].scfi[ch]){
case 0:
bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
break;
case 1:
bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];
break;
case 2:
bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
break;
case 3:
bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
break;
}
c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];
}
}
}
/* get quantizers */
memset(c->Q, 0, sizeof(c->Q));
off = 0;
for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)
for(ch = 0; ch < 2; ch++)
idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);
ff_mpc_dequantize_and_synth(c, mb, data, 2);
av_free(bits);
bits_used = get_bits_count(&gb);
bits_avail = (buf_size - 4) * 8;
if(!buf[1] && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))){
av_log(NULL,0, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);
return -1;
}
if(c->frames_to_skip){
c->frames_to_skip--;
*data_size = 0;
return buf_size;
}
*data_size = (buf[1] ? c->lastframelen : MPC_FRAME_SIZE) * 4;
return buf_size;
}
static void mpc7_decode_flush(AVCodecContext *avctx)
{
MPCContext *c = avctx->priv_data;
memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
c->frames_to_skip = 32;
}
AVCodec mpc7_decoder = {
"mpc7",
AVMEDIA_TYPE_AUDIO,
CODEC_ID_MUSEPACK7,
sizeof(MPCContext),
mpc7_decode_init,
NULL,
NULL,
mpc7_decode_frame,
.flush = mpc7_decode_flush,
.long_name = NULL_IF_CONFIG_SMALL("Musepack SV7"),
};