mirror of
https://git.videolan.org/git/ffmpeg.git
synced 2024-09-11 18:07:56 +02:00
652 lines
18 KiB
C
652 lines
18 KiB
C
/*
|
|
* FLAC (Free Lossless Audio Codec) decoder
|
|
* Copyright (c) 2003 Alex Beregszaszi
|
|
*
|
|
* This library 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 of the License, or (at your option) any later version.
|
|
*
|
|
* This library 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 this library; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
/**
|
|
* @file flac.c
|
|
* FLAC (Free Lossless Audio Codec) decoder
|
|
* @author Alex Beregszaszi
|
|
*/
|
|
|
|
#include "avcodec.h"
|
|
#include "golomb.h"
|
|
|
|
#define MAX_CHANNELS 8
|
|
#define MAX_BLOCKSIZE 65535
|
|
|
|
enum channel_order {
|
|
INDEPENDENT,
|
|
LEFT_SIDE,
|
|
RIGHT_SIDE,
|
|
MID_SIDE,
|
|
};
|
|
|
|
typedef struct FLACContext {
|
|
AVCodecContext *avctx;
|
|
GetBitContext gb;
|
|
|
|
int min_blocksize, max_blocksize;
|
|
int min_framesize, max_framesize;
|
|
int samplerate, channels;
|
|
int blocksize, last_blocksize;
|
|
int bps, curr_bps;
|
|
enum channel_order order;
|
|
|
|
uint8_t *residual[MAX_CHANNELS];
|
|
uint32_t *decoded[MAX_CHANNELS];
|
|
} FLACContext;
|
|
|
|
#define METADATA_TYPE_STREAMINFO 0
|
|
|
|
static int sample_rate_table[] =
|
|
{ 0, 0, 0, 0,
|
|
8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
|
|
0, 0, 0, 0 };
|
|
|
|
static int sample_size_table[] =
|
|
{ 0, 8, 12, 0, 16, 20, 24, 0 };
|
|
|
|
static uint64_t get_uvlc(GetBitContext *gb, int is64)
|
|
{
|
|
uint64_t val = 0;
|
|
int i = 0;
|
|
|
|
while(i++ < 5+is64)
|
|
{
|
|
const int tmp = get_bits(gb, 8);
|
|
|
|
if (tmp & 0x80)
|
|
val = (val << 7) + tmp - 0x80;
|
|
else
|
|
return (val << 7) + tmp;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static int flac_decode_init(AVCodecContext * avctx)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void dump_headers(FLACContext *s)
|
|
{
|
|
printf(" Blocksize: %d .. %d (%d)\n", s->min_blocksize, s->max_blocksize, s->blocksize);
|
|
printf(" Framesize: %d .. %d\n", s->min_framesize, s->max_framesize);
|
|
printf(" Samplerate: %d\n", s->samplerate);
|
|
printf(" Channels: %d\n", s->channels);
|
|
printf(" Bits: %d\n", s->bps);
|
|
}
|
|
|
|
static void metadata_streaminfo(FLACContext *s)
|
|
{
|
|
int i;
|
|
|
|
/* mandatory streaminfo */
|
|
s->min_blocksize = get_bits(&s->gb, 16);
|
|
s->max_blocksize = get_bits(&s->gb, 16);
|
|
|
|
s->min_framesize = get_bits_long(&s->gb, 24);
|
|
s->max_framesize = get_bits_long(&s->gb, 24);
|
|
|
|
s->samplerate = get_bits_long(&s->gb, 20);
|
|
s->channels = get_bits(&s->gb, 3) + 1;
|
|
s->bps = get_bits(&s->gb, 5) + 1;
|
|
|
|
s->avctx->channels = s->channels;
|
|
s->avctx->sample_rate = s->samplerate;
|
|
|
|
skip_bits(&s->gb, 36); /* total num of samples */
|
|
|
|
skip_bits(&s->gb, 64); /* md5 sum */
|
|
skip_bits(&s->gb, 64); /* md5 sum */
|
|
|
|
for (i = 0; i < s->channels; i++)
|
|
{
|
|
s->decoded[i] = av_realloc(s->decoded[i], sizeof(uint32_t)*s->max_blocksize);
|
|
s->residual[i] = av_realloc(s->residual[i], sizeof(uint8_t)*s->max_blocksize);
|
|
}
|
|
}
|
|
|
|
static int decode_residuals(FLACContext *s, int channel, int pred_order)
|
|
{
|
|
int i, tmp, partition, method_type, rice_order;
|
|
int sample = 0, samples;
|
|
|
|
method_type = get_bits(&s->gb, 2);
|
|
if (method_type != 0)
|
|
return -1;
|
|
|
|
rice_order = get_bits(&s->gb, 4);
|
|
|
|
samples = (rice_order > 0) ?
|
|
(s->blocksize >> rice_order) : (s->blocksize - pred_order);
|
|
|
|
for (partition = 0; partition < (1 << rice_order); partition++)
|
|
{
|
|
tmp = get_bits(&s->gb, 4);
|
|
if (tmp == 0)
|
|
{
|
|
i = (!rice_order || partition) ? 0 : pred_order;
|
|
for (; i < samples; i++, sample++)
|
|
s->residual[channel][sample] = get_sr_golomb_flac(&s->gb, tmp, 0, 0);
|
|
printf("zero k\n");
|
|
}
|
|
else if (tmp == 15)
|
|
{
|
|
printf("fixed len partition\n");
|
|
tmp = get_bits(&s->gb, 5);
|
|
i = (!rice_order || partition) ? 0 : pred_order;
|
|
for (; i < samples; i++, sample++)
|
|
s->residual[channel][sample] = get_bits(&s->gb, tmp);
|
|
}
|
|
else
|
|
{
|
|
// printf("rice coded partition\n");
|
|
#if 1
|
|
i = (!rice_order || partition) ? 0 : pred_order;
|
|
for (; i < samples; i++, sample++)
|
|
s->residual[channel][sample] = get_sr_golomb_flac(&s->gb, tmp, 0, 0);
|
|
#else
|
|
i = ((!rice_order || partition) ? samples : samples - pred_order) + sample;
|
|
for (; sample < i; sample++)
|
|
s->residual[channel][sample] = get_ur_golomb(&s->gb, tmp, 0, 0);
|
|
// s->residual[channel][sample] = get_se_golomb(&s->gb);
|
|
#endif
|
|
}
|
|
}
|
|
|
|
printf("partitions: %d, samples: %d\n", 1 << rice_order, sample);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int decode_subframe_fixed(FLACContext *s, int channel, int pred_order)
|
|
{
|
|
int i;
|
|
|
|
printf(" SUBFRAME FIXED\n");
|
|
|
|
/* warm up samples */
|
|
printf(" warm up samples: %d\n", pred_order);
|
|
|
|
for (i = 0; i < pred_order; i++)
|
|
{
|
|
s->decoded[channel][i] = get_bits(&s->gb, s->curr_bps);
|
|
printf(" %d: %d\n", i, s->decoded[channel][i]);
|
|
}
|
|
|
|
if (decode_residuals(s, channel, pred_order) < 0)
|
|
return -1;
|
|
|
|
switch(pred_order)
|
|
{
|
|
case 0:
|
|
for (i = pred_order; i < s->blocksize; i++)
|
|
s->decoded[channel][i] = s->residual[channel][i];
|
|
break;
|
|
case 1:
|
|
for (i = pred_order; i < s->blocksize; i++)
|
|
s->decoded[channel][i] = s->residual[channel][i] +
|
|
s->decoded[channel][i-1];
|
|
break;
|
|
case 2:
|
|
for (i = pred_order; i < s->blocksize; i++)
|
|
s->decoded[channel][i] = s->residual[channel][i] +
|
|
(s->decoded[channel][i-1] << 1) -
|
|
s->decoded[channel][i-2];
|
|
break;
|
|
case 3:
|
|
for (i = pred_order; i < s->blocksize; i++)
|
|
s->decoded[channel][i] = s->residual[channel][i] +
|
|
(((s->decoded[channel][i-1] -
|
|
s->decoded[channel][i-2]) << 1) +
|
|
(s->decoded[channel][i-1] -
|
|
s->decoded[channel][i-2])) +
|
|
s->decoded[channel][i-3];
|
|
break;
|
|
case 4:
|
|
for (i = pred_order; i < s->blocksize; i++)
|
|
s->decoded[channel][i] = s->residual[channel][i] +
|
|
((s->decoded[channel][i-1] +
|
|
s->decoded[channel][i-3]) << 2) -
|
|
((s->decoded[channel][i-2] << 2) +
|
|
(s->decoded[channel][i-2] << 1)) -
|
|
s->decoded[channel][i-4];
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int decode_subframe_lpc(FLACContext *s, int channel, int pred_order)
|
|
{
|
|
int sum, i, j;
|
|
int coeff_prec, qlevel;
|
|
int coeffs[pred_order];
|
|
|
|
printf(" SUBFRAME LPC\n");
|
|
|
|
/* warm up samples */
|
|
printf(" warm up samples: %d\n", pred_order);
|
|
|
|
for (i = 0; i < pred_order; i++)
|
|
{
|
|
s->decoded[channel][i] = get_bits(&s->gb, s->curr_bps);
|
|
printf(" %d: %d\n", i, s->decoded[channel][i]);
|
|
}
|
|
|
|
coeff_prec = get_bits(&s->gb, 4) + 1;
|
|
if (coeff_prec == 16)
|
|
{
|
|
printf("invalid coeff precision\n");
|
|
return -1;
|
|
}
|
|
printf(" qlp coeff prec: %d\n", coeff_prec);
|
|
qlevel = get_bits(&s->gb, 5);
|
|
printf(" quant level: %d\n", qlevel);
|
|
|
|
for (i = 0; i < pred_order; i++)
|
|
{
|
|
coeffs[i] = get_bits(&s->gb, coeff_prec);
|
|
printf(" %d: %d\n", i, coeffs[i]);
|
|
}
|
|
|
|
if (decode_residuals(s, channel, pred_order) < 0)
|
|
return -1;
|
|
|
|
for (i = pred_order; i < s->blocksize; i++)
|
|
{
|
|
sum = 0;
|
|
for (j = 0; j < pred_order; j++)
|
|
sum += coeffs[j] * s->decoded[channel][i-j-1];
|
|
s->decoded[channel][i] = s->residual[channel][i] + (sum >> qlevel);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int decode_subframe(FLACContext *s, int channel)
|
|
{
|
|
int type, wasted = 0;
|
|
int i, tmp;
|
|
|
|
s->curr_bps = s->bps;
|
|
|
|
if (get_bits1(&s->gb))
|
|
{
|
|
printf("invalid subframe padding\n");
|
|
return -1;
|
|
}
|
|
type = get_bits(&s->gb, 6);
|
|
// wasted = get_bits1(&s->gb);
|
|
|
|
// if (wasted)
|
|
// {
|
|
// while (!get_bits1(&s->gb))
|
|
// wasted++;
|
|
// if (wasted)
|
|
// wasted++;
|
|
// s->curr_bps -= wasted;
|
|
// }
|
|
|
|
if (get_bits1(&s->gb))
|
|
{
|
|
wasted = 1;
|
|
while (!get_bits1(&s->gb))
|
|
wasted++;
|
|
s->curr_bps -= wasted;
|
|
}
|
|
|
|
if (type == 0)
|
|
{
|
|
printf("coding type: constant\n");
|
|
tmp = get_bits(&s->gb, s->curr_bps);
|
|
for (i = 0; i < s->blocksize; i++)
|
|
s->decoded[channel][i] = tmp;
|
|
}
|
|
else if (type == 1)
|
|
{
|
|
printf("coding type: verbatim\n");
|
|
for (i = 0; i < s->blocksize; i++)
|
|
s->decoded[channel][i] = get_bits(&s->gb, s->curr_bps);
|
|
}
|
|
else if ((type >= 8) && (type <= 12))
|
|
{
|
|
printf("coding type: fixed\n");
|
|
if (decode_subframe_fixed(s, channel, type & ~0x8) < 0)
|
|
return -1;
|
|
}
|
|
else if (type >= 32)
|
|
{
|
|
printf("coding type: lpc\n");
|
|
if (decode_subframe_lpc(s, channel, (type & ~0x20)+1) < 0)
|
|
return -1;
|
|
}
|
|
else
|
|
{
|
|
printf("invalid coding type\n");
|
|
return -1;
|
|
}
|
|
|
|
if (wasted)
|
|
{
|
|
int i;
|
|
for (i = 0; i < s->blocksize; i++)
|
|
s->decoded[channel][i] <<= wasted;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int decode_frame(FLACContext *s)
|
|
{
|
|
int blocksize_code, sample_rate_code, sample_size_code, assignment, i;
|
|
|
|
blocksize_code = get_bits(&s->gb, 4);
|
|
if (blocksize_code == 0)
|
|
s->blocksize = s->min_blocksize;
|
|
else if (blocksize_code == 1)
|
|
s->blocksize = 192;
|
|
else if (blocksize_code <= 5)
|
|
s->blocksize = 576 << (blocksize_code - 2);
|
|
else if (blocksize_code >= 8)
|
|
s->blocksize = 256 << (blocksize_code - 8);
|
|
|
|
sample_rate_code = get_bits(&s->gb, 4);
|
|
if ((sample_rate_code > 3) && (sample_rate_code < 12))
|
|
s->samplerate = sample_rate_table[sample_rate_code];
|
|
|
|
assignment = get_bits(&s->gb, 4); /* channel assignment */
|
|
if (assignment < 8)
|
|
{
|
|
s->order = INDEPENDENT;
|
|
if (s->channels != assignment+1)
|
|
printf("channel number and number of assigned channels differ!\n");
|
|
printf("channels: %d\n", assignment+1);
|
|
}
|
|
else if (assignment == 8)
|
|
{
|
|
s->order = LEFT_SIDE;
|
|
printf("left/side\n");
|
|
}
|
|
else if (assignment == 9)
|
|
{
|
|
s->order = RIGHT_SIDE;
|
|
printf("right/side\n");
|
|
}
|
|
else if (assignment == 10)
|
|
{
|
|
s->order = MID_SIDE;
|
|
printf("mid/side\n");
|
|
}
|
|
else
|
|
{
|
|
printf("unsupported channel assignment\n");
|
|
return -1;
|
|
}
|
|
|
|
if ((assignment >= 8) && (s->channels != 2))
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
sample_size_code = get_bits(&s->gb, 3);
|
|
if (s->bps != 0)
|
|
s->bps = sample_size_table[sample_size_code];
|
|
|
|
if ((sample_size_code == 3) || (sample_size_code == 7))
|
|
{
|
|
printf("invalid sample size code (%d)\n", sample_size_code);
|
|
return -1;
|
|
}
|
|
|
|
if (get_bits1(&s->gb))
|
|
{
|
|
printf("broken stream, invalid padding\n");
|
|
// return -1;
|
|
}
|
|
|
|
if (((blocksize_code == 6) || (blocksize_code == 7)) &&
|
|
(s->min_blocksize != s->max_blocksize))
|
|
{
|
|
get_uvlc(&s->gb, 1);
|
|
}
|
|
else
|
|
get_uvlc(&s->gb, 0);
|
|
|
|
if (blocksize_code == 6)
|
|
s->blocksize = get_bits(&s->gb, 8)+1;
|
|
if (blocksize_code == 7)
|
|
s->blocksize = get_bits(&s->gb, 16)+1;
|
|
|
|
if ((sample_rate_code > 11) && (sample_rate_code < 15))
|
|
{
|
|
switch(sample_rate_code)
|
|
{
|
|
case 12:
|
|
s->samplerate = get_bits(&s->gb, 8) * 1000;
|
|
break;
|
|
case 13:
|
|
s->samplerate = get_bits(&s->gb, 16);
|
|
break;
|
|
case 14:
|
|
s->samplerate = get_bits(&s->gb, 16) * 10;
|
|
break;
|
|
}
|
|
}
|
|
|
|
skip_bits(&s->gb, 8); /* header crc */
|
|
|
|
dump_headers(s);
|
|
|
|
/* subframes */
|
|
for (i = 0; i < s->channels; i++)
|
|
{
|
|
if (s->blocksize != s->last_blocksize)
|
|
{
|
|
s->decoded[i] = av_realloc(s->decoded[i], sizeof(uint32_t)*s->blocksize);
|
|
s->residual[i] = av_realloc(s->residual[i], sizeof(uint8_t)*s->blocksize);
|
|
}
|
|
printf("decoded: %x residual: %x\n", s->decoded[i], s->residual[i]);
|
|
if (decode_subframe(s, i) < 0)
|
|
return -1;
|
|
}
|
|
|
|
align_get_bits(&s->gb);
|
|
|
|
/* frame footer */
|
|
skip_bits(&s->gb, 16); /* data crc */
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int flac_decode_frame(AVCodecContext *avctx,
|
|
void *data, int *data_size,
|
|
uint8_t *buf, int buf_size)
|
|
{
|
|
FLACContext *s = avctx->priv_data;
|
|
int metadata_flag, metadata_type, metadata_size;
|
|
int tmp = 0, i, j = 0;
|
|
int16_t *samples = data, *left, *right;
|
|
|
|
*data_size = 0;
|
|
|
|
s->avctx = avctx;
|
|
|
|
init_get_bits(&s->gb, buf, buf_size*8);
|
|
|
|
/* fLaC signature (be) */
|
|
if (get_bits_long(&s->gb, 32) == bswap_32(ff_get_fourcc("fLaC")))
|
|
{
|
|
printf("STREAM HEADER\n");
|
|
do {
|
|
metadata_flag = get_bits(&s->gb, 1);
|
|
metadata_type = get_bits(&s->gb, 7);
|
|
metadata_size = get_bits_long(&s->gb, 24);
|
|
|
|
printf(" metadata block: flag = %d, type = %d, size = %d\n",
|
|
metadata_flag, metadata_type,
|
|
metadata_size);
|
|
|
|
switch(metadata_type)
|
|
{
|
|
case METADATA_TYPE_STREAMINFO:
|
|
metadata_streaminfo(s);
|
|
dump_headers(s);
|
|
break;
|
|
default:
|
|
while ((metadata_size -= 8) > 0)
|
|
skip_bits(&s->gb, 8);
|
|
}
|
|
} while(metadata_flag != 1);
|
|
}
|
|
else
|
|
{
|
|
init_get_bits(&s->gb, buf, buf_size*8);
|
|
tmp = get_bits(&s->gb, 16);
|
|
if (tmp == 0xfff8)
|
|
printf("FRAME HEADER\n");
|
|
|
|
if (decode_frame(s) < 0)
|
|
return -1;
|
|
}
|
|
|
|
#if 0
|
|
/* fix the channel order here */
|
|
if (s->order == MID_SIDE)
|
|
{
|
|
short *left = samples;
|
|
short *right = samples + s->blocksize;
|
|
for (i = 0; i < s->blocksize; i += 2)
|
|
{
|
|
uint32_t x = s->decoded[0][i];
|
|
uint32_t y = s->decoded[0][i+1];
|
|
|
|
right[i] = x - (y / 2);
|
|
left[i] = right[i] + y;
|
|
}
|
|
*data_size = 2 * s->blocksize;
|
|
}
|
|
else
|
|
{
|
|
for (i = 0; i < s->channels; i++)
|
|
{
|
|
switch(s->order)
|
|
{
|
|
case INDEPENDENT:
|
|
for (j = 0; j < s->blocksize; j++)
|
|
samples[(s->blocksize*i)+j] = s->decoded[i][j];
|
|
break;
|
|
case LEFT_SIDE:
|
|
case RIGHT_SIDE:
|
|
if (i == 0)
|
|
for (j = 0; j < s->blocksize; j++)
|
|
samples[(s->blocksize*i)+j] = s->decoded[0][j];
|
|
else
|
|
for (j = 0; j < s->blocksize; j++)
|
|
samples[(s->blocksize*i)+j] = s->decoded[0][j] - s->decoded[i][j];
|
|
break;
|
|
// case MID_SIDE:
|
|
// printf("mid-side unsupported\n");
|
|
}
|
|
*data_size += s->blocksize;
|
|
}
|
|
}
|
|
#else
|
|
switch(s->order)
|
|
{
|
|
case INDEPENDENT:
|
|
for (i = 0; i < s->channels; i++)
|
|
{
|
|
for (j = 0; j < s->blocksize; j++)
|
|
*(samples++) = s->decoded[i][j];
|
|
*data_size += s->blocksize;
|
|
}
|
|
break;
|
|
case LEFT_SIDE:
|
|
assert(s->channels == 2);
|
|
for (i = 0; i < s->blocksize; i++)
|
|
{
|
|
*(samples++) = s->decoded[0][i];
|
|
*(samples++) = s->decoded[0][i] - s->decoded[1][i];
|
|
}
|
|
*data_size = 2*s->blocksize;
|
|
break;
|
|
case RIGHT_SIDE:
|
|
assert(s->channels == 2);
|
|
for (i = 0; i < s->blocksize; i++)
|
|
{
|
|
*(samples++) = s->decoded[0][i] + s->decoded[1][i];
|
|
*(samples++) = s->decoded[1][i];
|
|
}
|
|
*data_size = 2*s->blocksize;
|
|
break;
|
|
case MID_SIDE:
|
|
assert(s->channels == 2);
|
|
for (i = 0; i < s->blocksize; i++)
|
|
{
|
|
int16_t mid, side;
|
|
mid = s->decoded[0][i];
|
|
side = s->decoded[1][i];
|
|
|
|
mid <<= 1;
|
|
if (side & 1)
|
|
mid++;
|
|
*(samples++) = (mid + side) >> 1;
|
|
*(samples++) = (mid - side) >> 1;
|
|
}
|
|
*data_size = 2*s->blocksize;
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
// *data_size = (int8_t *)samples - (int8_t *)data;
|
|
printf("data size: %d\n", *data_size);
|
|
|
|
s->last_blocksize = s->blocksize;
|
|
|
|
return (get_bits_count(&s->gb)+7)/8;
|
|
}
|
|
|
|
static int flac_decode_close(AVCodecContext *avctx)
|
|
{
|
|
FLACContext *s = avctx->priv_data;
|
|
int i;
|
|
|
|
for (i = 0; i < s->channels; i++)
|
|
{
|
|
if (s->decoded[i])
|
|
av_free(s->decoded[i]);
|
|
if (s->residual[i])
|
|
av_free(s->residual[i]);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
AVCodec flac_decoder = {
|
|
"flac",
|
|
CODEC_TYPE_AUDIO,
|
|
CODEC_ID_FLAC,
|
|
sizeof(FLACContext),
|
|
flac_decode_init,
|
|
NULL,
|
|
flac_decode_close,
|
|
flac_decode_frame,
|
|
};
|