mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-23 12:43:46 +02:00
adts aac parser
Originally committed as revision 4954 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
parent
79b0b66ba0
commit
da46276ff8
@ -622,5 +622,6 @@ PCM_CODEC(CODEC_ID_ADPCM_YAMAHA, adpcm_yamaha);
|
||||
#ifdef CONFIG_DVBSUB_DECODER
|
||||
av_register_codec_parser(&dvbsub_parser);
|
||||
#endif
|
||||
av_register_codec_parser(&aac_parser);
|
||||
}
|
||||
|
||||
|
@ -2516,6 +2516,7 @@ extern AVCodecParser mpegaudio_parser;
|
||||
extern AVCodecParser ac3_parser;
|
||||
extern AVCodecParser dvdsub_parser;
|
||||
extern AVCodecParser dvbsub_parser;
|
||||
extern AVCodecParser aac_parser;
|
||||
|
||||
/* memory */
|
||||
void *av_malloc(unsigned int size);
|
||||
|
@ -727,13 +727,18 @@ static int mpegaudio_parse(AVCodecParserContext *s1,
|
||||
return buf_ptr - buf;
|
||||
}
|
||||
|
||||
/* also used for ADTS AAC */
|
||||
typedef struct AC3ParseContext {
|
||||
uint8_t inbuf[4096]; /* input buffer */
|
||||
uint8_t *inbuf_ptr;
|
||||
int frame_size;
|
||||
int header_size;
|
||||
int (*sync)(const uint8_t *buf, int *channels, int *sample_rate,
|
||||
int *bit_rate, int *samples);
|
||||
} AC3ParseContext;
|
||||
|
||||
#define AC3_HEADER_SIZE 7
|
||||
#define AAC_HEADER_SIZE 8
|
||||
|
||||
static const int ac3_sample_rates[4] = {
|
||||
48000, 44100, 32000, 0
|
||||
@ -790,8 +795,17 @@ static const int ac3_channels[8] = {
|
||||
2, 1, 2, 3, 3, 4, 4, 5
|
||||
};
|
||||
|
||||
static int aac_sample_rates[16] = {
|
||||
96000, 88200, 64000, 48000, 44100, 32000,
|
||||
24000, 22050, 16000, 12000, 11025, 8000, 7350
|
||||
};
|
||||
|
||||
static int aac_channels[8] = {
|
||||
0, 1, 2, 3, 4, 5, 6, 8
|
||||
};
|
||||
|
||||
static int ac3_sync(const uint8_t *buf, int *channels, int *sample_rate,
|
||||
int *bit_rate)
|
||||
int *bit_rate, int *samples)
|
||||
{
|
||||
unsigned int fscod, frmsizecod, acmod, bsid, lfeon;
|
||||
GetBitContext bits;
|
||||
@ -824,17 +838,70 @@ static int ac3_sync(const uint8_t *buf, int *channels, int *sample_rate,
|
||||
*sample_rate = ac3_sample_rates[fscod];
|
||||
*bit_rate = ac3_bitrates[frmsizecod] * 1000;
|
||||
*channels = ac3_channels[acmod] + lfeon;
|
||||
*samples = 6 * 256;
|
||||
|
||||
return ac3_frame_sizes[frmsizecod][fscod] * 2;
|
||||
}
|
||||
|
||||
static int aac_sync(const uint8_t *buf, int *channels, int *sample_rate,
|
||||
int *bit_rate, int *samples)
|
||||
{
|
||||
GetBitContext bits;
|
||||
int size, rdb, ch, sr;
|
||||
|
||||
init_get_bits(&bits, buf, AAC_HEADER_SIZE * 8);
|
||||
|
||||
if(get_bits(&bits, 12) != 0xfff)
|
||||
return 0;
|
||||
|
||||
get_bits(&bits, 1);
|
||||
get_bits(&bits, 2);
|
||||
get_bits(&bits, 1); /* protection_absent */
|
||||
get_bits(&bits, 2);
|
||||
sr = get_bits(&bits, 4);
|
||||
if(!aac_sample_rates[sr])
|
||||
return 0;
|
||||
get_bits(&bits, 1); /* private_bit */
|
||||
ch = get_bits(&bits, 3);
|
||||
if(!aac_channels[ch])
|
||||
return 0;
|
||||
get_bits(&bits, 1); /* original/copy */
|
||||
get_bits(&bits, 1); /* home */
|
||||
|
||||
/* adts_variable_header */
|
||||
get_bits(&bits, 1); /* copyright_identification_bit */
|
||||
get_bits(&bits, 1); /* copyright_identification_start */
|
||||
size = get_bits(&bits, 13);
|
||||
get_bits(&bits, 11); /* adts_buffer_fullness */
|
||||
rdb = get_bits(&bits, 2);
|
||||
|
||||
*channels = aac_channels[ch];
|
||||
*sample_rate = aac_sample_rates[sr];
|
||||
*samples = (rdb + 1) * 1024;
|
||||
*bit_rate = size * 8 * *sample_rate / *samples;
|
||||
|
||||
return size;
|
||||
}
|
||||
|
||||
static int ac3_parse_init(AVCodecParserContext *s1)
|
||||
{
|
||||
AC3ParseContext *s = s1->priv_data;
|
||||
s->inbuf_ptr = s->inbuf;
|
||||
s->header_size = AC3_HEADER_SIZE;
|
||||
s->sync = ac3_sync;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int aac_parse_init(AVCodecParserContext *s1)
|
||||
{
|
||||
AC3ParseContext *s = s1->priv_data;
|
||||
s->inbuf_ptr = s->inbuf;
|
||||
s->header_size = AAC_HEADER_SIZE;
|
||||
s->sync = aac_sync;
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* also used for ADTS AAC */
|
||||
static int ac3_parse(AVCodecParserContext *s1,
|
||||
AVCodecContext *avctx,
|
||||
uint8_t **poutbuf, int *poutbuf_size,
|
||||
@ -842,7 +909,7 @@ static int ac3_parse(AVCodecParserContext *s1,
|
||||
{
|
||||
AC3ParseContext *s = s1->priv_data;
|
||||
const uint8_t *buf_ptr;
|
||||
int len, sample_rate, bit_rate, channels;
|
||||
int len, sample_rate, bit_rate, channels, samples;
|
||||
|
||||
*poutbuf = NULL;
|
||||
*poutbuf_size = 0;
|
||||
@ -851,29 +918,35 @@ static int ac3_parse(AVCodecParserContext *s1,
|
||||
while (buf_size > 0) {
|
||||
len = s->inbuf_ptr - s->inbuf;
|
||||
if (s->frame_size == 0) {
|
||||
/* no header seen : find one. We need at least 7 bytes to parse it */
|
||||
len = FFMIN(AC3_HEADER_SIZE - len, buf_size);
|
||||
/* no header seen : find one. We need at least s->header_size
|
||||
bytes to parse it */
|
||||
len = FFMIN(s->header_size - len, buf_size);
|
||||
|
||||
memcpy(s->inbuf_ptr, buf_ptr, len);
|
||||
buf_ptr += len;
|
||||
s->inbuf_ptr += len;
|
||||
buf_size -= len;
|
||||
if ((s->inbuf_ptr - s->inbuf) == AC3_HEADER_SIZE) {
|
||||
len = ac3_sync(s->inbuf, &channels, &sample_rate, &bit_rate);
|
||||
if ((s->inbuf_ptr - s->inbuf) == s->header_size) {
|
||||
len = s->sync(s->inbuf, &channels, &sample_rate, &bit_rate,
|
||||
&samples);
|
||||
if (len == 0) {
|
||||
/* no sync found : move by one byte (inefficient, but simple!) */
|
||||
memmove(s->inbuf, s->inbuf + 1, AC3_HEADER_SIZE - 1);
|
||||
memmove(s->inbuf, s->inbuf + 1, s->header_size - 1);
|
||||
s->inbuf_ptr--;
|
||||
} else {
|
||||
s->frame_size = len;
|
||||
/* update codec info */
|
||||
avctx->sample_rate = sample_rate;
|
||||
/* set channels,except if the user explicitly requests 1 or 2 channels, XXX/FIXME this is a bit ugly */
|
||||
if(avctx->channels!=1 && avctx->channels!=2){
|
||||
if(avctx->codec_id == CODEC_ID_AC3){
|
||||
if(avctx->channels!=1 && avctx->channels!=2){
|
||||
avctx->channels = channels;
|
||||
}
|
||||
} else {
|
||||
avctx->channels = channels;
|
||||
}
|
||||
avctx->bit_rate = bit_rate;
|
||||
avctx->frame_size = 6 * 256;
|
||||
avctx->frame_size = samples;
|
||||
}
|
||||
}
|
||||
} else {
|
||||
@ -929,3 +1002,11 @@ AVCodecParser ac3_parser = {
|
||||
ac3_parse,
|
||||
NULL,
|
||||
};
|
||||
|
||||
AVCodecParser aac_parser = {
|
||||
{ CODEC_ID_AAC },
|
||||
sizeof(AC3ParseContext),
|
||||
aac_parse_init,
|
||||
ac3_parse,
|
||||
NULL,
|
||||
};
|
||||
|
Loading…
Reference in New Issue
Block a user