mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-26 19:01:44 +02:00
Move decode_frame_header() from flacdec.c to flac.c/h to share with the
forthcoming FLAC parser. Patch by Michael Chinen [mchinen at gmail] Originally committed as revision 25909 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Chinen
Justin Ruggles
parent
86b6e387cc
commit
625daac4bd
@ -19,7 +19,101 @@
|
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
||||
*/
|
||||
|
||||
#include "libavutil/crc.h"
|
||||
#include "flac.h"
|
||||
#include "flacdata.h"
|
||||
|
||||
static const int8_t sample_size_table[] = { 0, 8, 12, 0, 16, 20, 24, 0 };
|
||||
|
||||
static int64_t get_utf8(GetBitContext *gb)
|
||||
{
|
||||
int64_t val;
|
||||
GET_UTF8(val, get_bits(gb, 8), return -1;)
|
||||
return val;
|
||||
}
|
||||
|
||||
int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
|
||||
FLACFrameInfo *fi)
|
||||
{
|
||||
int bs_code, sr_code, bps_code;
|
||||
|
||||
/* frame sync code */
|
||||
skip_bits(gb, 16);
|
||||
|
||||
/* block size and sample rate codes */
|
||||
bs_code = get_bits(gb, 4);
|
||||
sr_code = get_bits(gb, 4);
|
||||
|
||||
/* channels and decorrelation */
|
||||
fi->ch_mode = get_bits(gb, 4);
|
||||
if (fi->ch_mode < FLAC_MAX_CHANNELS) {
|
||||
fi->channels = fi->ch_mode + 1;
|
||||
fi->ch_mode = FLAC_CHMODE_INDEPENDENT;
|
||||
} else if (fi->ch_mode <= FLAC_CHMODE_MID_SIDE) {
|
||||
fi->channels = 2;
|
||||
} else {
|
||||
av_log(avctx, AV_LOG_ERROR, "invalid channel mode: %d\n", fi->ch_mode);
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* bits per sample */
|
||||
bps_code = get_bits(gb, 3);
|
||||
if (bps_code == 3 || bps_code == 7) {
|
||||
av_log(avctx, AV_LOG_ERROR, "invalid sample size code (%d)\n",
|
||||
bps_code);
|
||||
return -1;
|
||||
}
|
||||
fi->bps = sample_size_table[bps_code];
|
||||
|
||||
/* reserved bit */
|
||||
if (get_bits1(gb)) {
|
||||
av_log(avctx, AV_LOG_ERROR, "broken stream, invalid padding\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* sample or frame count */
|
||||
if (get_utf8(gb) < 0) {
|
||||
av_log(avctx, AV_LOG_ERROR, "utf8 fscked\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* blocksize */
|
||||
if (bs_code == 0) {
|
||||
av_log(avctx, AV_LOG_ERROR, "reserved blocksize code: 0\n");
|
||||
return -1;
|
||||
} else if (bs_code == 6) {
|
||||
fi->blocksize = get_bits(gb, 8) + 1;
|
||||
} else if (bs_code == 7) {
|
||||
fi->blocksize = get_bits(gb, 16) + 1;
|
||||
} else {
|
||||
fi->blocksize = ff_flac_blocksize_table[bs_code];
|
||||
}
|
||||
|
||||
/* sample rate */
|
||||
if (sr_code < 12) {
|
||||
fi->samplerate = ff_flac_sample_rate_table[sr_code];
|
||||
} else if (sr_code == 12) {
|
||||
fi->samplerate = get_bits(gb, 8) * 1000;
|
||||
} else if (sr_code == 13) {
|
||||
fi->samplerate = get_bits(gb, 16);
|
||||
} else if (sr_code == 14) {
|
||||
fi->samplerate = get_bits(gb, 16) * 10;
|
||||
} else {
|
||||
av_log(avctx, AV_LOG_ERROR, "illegal sample rate code %d\n",
|
||||
sr_code);
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* header CRC-8 check */
|
||||
skip_bits(gb, 8);
|
||||
if (av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, gb->buffer,
|
||||
get_bits_count(gb)/8)) {
|
||||
av_log(avctx, AV_LOG_ERROR, "header crc mismatch\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int ff_flac_get_max_frame_size(int blocksize, int ch, int bps)
|
||||
{
|
||||
|
||||
@ -28,6 +28,7 @@
|
||||
#define AVCODEC_FLAC_H
|
||||
|
||||
#include "avcodec.h"
|
||||
#include "get_bits.h"
|
||||
|
||||
#define FLAC_STREAMINFO_SIZE 34
|
||||
#define FLAC_MAX_CHANNELS 8
|
||||
@ -120,4 +121,13 @@ void ff_flac_parse_block_header(const uint8_t *block_header,
|
||||
*/
|
||||
int ff_flac_get_max_frame_size(int blocksize, int ch, int bps);
|
||||
|
||||
/**
|
||||
* Validate and decode a frame header.
|
||||
* @param avctx AVCodecContext to use as av_log() context
|
||||
* @param gb GetBitContext from which to read frame header
|
||||
* @param[out] fi frame information
|
||||
* @return non-zero on error, 0 if ok
|
||||
*/
|
||||
int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
|
||||
FLACFrameInfo *fi);
|
||||
#endif /* AVCODEC_FLAC_H */
|
||||
|
||||
@ -67,16 +67,6 @@ typedef struct FLACContext {
|
||||
unsigned int allocated_bitstream_size;
|
||||
} FLACContext;
|
||||
|
||||
static const int sample_size_table[] =
|
||||
{ 0, 8, 12, 0, 16, 20, 24, 0 };
|
||||
|
||||
static int64_t get_utf8(GetBitContext *gb)
|
||||
{
|
||||
int64_t val;
|
||||
GET_UTF8(val, get_bits(gb, 8), return -1;)
|
||||
return val;
|
||||
}
|
||||
|
||||
static void allocate_buffers(FLACContext *s);
|
||||
|
||||
int ff_flac_is_extradata_valid(AVCodecContext *avctx,
|
||||
@ -480,103 +470,13 @@ static inline int decode_subframe(FLACContext *s, int channel)
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* Validate and decode a frame header.
|
||||
* @param avctx AVCodecContext to use as av_log() context
|
||||
* @param gb GetBitContext from which to read frame header
|
||||
* @param[out] fi frame information
|
||||
* @return non-zero on error, 0 if ok
|
||||
*/
|
||||
static int decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
|
||||
FLACFrameInfo *fi)
|
||||
{
|
||||
int bs_code, sr_code, bps_code;
|
||||
|
||||
/* frame sync code */
|
||||
skip_bits(gb, 16);
|
||||
|
||||
/* block size and sample rate codes */
|
||||
bs_code = get_bits(gb, 4);
|
||||
sr_code = get_bits(gb, 4);
|
||||
|
||||
/* channels and decorrelation */
|
||||
fi->ch_mode = get_bits(gb, 4);
|
||||
if (fi->ch_mode < FLAC_MAX_CHANNELS) {
|
||||
fi->channels = fi->ch_mode + 1;
|
||||
fi->ch_mode = FLAC_CHMODE_INDEPENDENT;
|
||||
} else if (fi->ch_mode <= FLAC_CHMODE_MID_SIDE) {
|
||||
fi->channels = 2;
|
||||
} else {
|
||||
av_log(avctx, AV_LOG_ERROR, "invalid channel mode: %d\n", fi->ch_mode);
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* bits per sample */
|
||||
bps_code = get_bits(gb, 3);
|
||||
if (bps_code == 3 || bps_code == 7) {
|
||||
av_log(avctx, AV_LOG_ERROR, "invalid sample size code (%d)\n",
|
||||
bps_code);
|
||||
return -1;
|
||||
}
|
||||
fi->bps = sample_size_table[bps_code];
|
||||
|
||||
/* reserved bit */
|
||||
if (get_bits1(gb)) {
|
||||
av_log(avctx, AV_LOG_ERROR, "broken stream, invalid padding\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* sample or frame count */
|
||||
if (get_utf8(gb) < 0) {
|
||||
av_log(avctx, AV_LOG_ERROR, "utf8 fscked\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* blocksize */
|
||||
if (bs_code == 0) {
|
||||
av_log(avctx, AV_LOG_ERROR, "reserved blocksize code: 0\n");
|
||||
return -1;
|
||||
} else if (bs_code == 6) {
|
||||
fi->blocksize = get_bits(gb, 8) + 1;
|
||||
} else if (bs_code == 7) {
|
||||
fi->blocksize = get_bits(gb, 16) + 1;
|
||||
} else {
|
||||
fi->blocksize = ff_flac_blocksize_table[bs_code];
|
||||
}
|
||||
|
||||
/* sample rate */
|
||||
if (sr_code < 12) {
|
||||
fi->samplerate = ff_flac_sample_rate_table[sr_code];
|
||||
} else if (sr_code == 12) {
|
||||
fi->samplerate = get_bits(gb, 8) * 1000;
|
||||
} else if (sr_code == 13) {
|
||||
fi->samplerate = get_bits(gb, 16);
|
||||
} else if (sr_code == 14) {
|
||||
fi->samplerate = get_bits(gb, 16) * 10;
|
||||
} else {
|
||||
av_log(avctx, AV_LOG_ERROR, "illegal sample rate code %d\n",
|
||||
sr_code);
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* header CRC-8 check */
|
||||
skip_bits(gb, 8);
|
||||
if (av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, gb->buffer,
|
||||
get_bits_count(gb)/8)) {
|
||||
av_log(avctx, AV_LOG_ERROR, "header crc mismatch\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int decode_frame(FLACContext *s)
|
||||
{
|
||||
int i;
|
||||
GetBitContext *gb = &s->gb;
|
||||
FLACFrameInfo fi;
|
||||
|
||||
if (decode_frame_header(s->avctx, gb, &fi)) {
|
||||
if (ff_flac_decode_frame_header(s->avctx, gb, &fi)) {
|
||||
av_log(s->avctx, AV_LOG_ERROR, "invalid frame header\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user