Commit 4770b1b4 authored by Roberto Togni's avatar Roberto Togni
Browse files

AVC (H264 in mp4 files, fourcc avc1) support

Originally committed as revision 3459 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent c08a01a6
......@@ -151,6 +151,13 @@ typedef struct H264Context{
uint8_t *rbsp_buffer;
int rbsp_buffer_size;
/**
* Used to parse AVC variant of h264
*/
int is_avc; ///< this flag is != 0 if codec is avc1
int got_avcC; ///< flag used to parse avcC data only once
int nal_length_size; ///< Number of bytes used for nal length (1, 2 or 4)
int chroma_qp; //QPc
int prev_mb_skiped; //FIXME remove (IMHO not used)
......@@ -2264,6 +2271,17 @@ static int decode_init(AVCodecContext *avctx){
decode_init_vlc(h);
if(avctx->codec_tag != 0x31637661) // avc1
h->is_avc = 0;
else {
if((avctx->extradata_size == 0) || (avctx->extradata == NULL)) {
av_log(avctx, AV_LOG_ERROR, "AVC codec requires avcC data\n");
return -1;
}
h->is_avc = 1;
h->got_avcC = 0;
}
return 0;
}
......@@ -5601,7 +5619,14 @@ static int decode_nal_units(H264Context *h, uint8_t *buf, int buf_size){
int dst_length;
int bit_length;
uint8_t *ptr;
int i, nalsize = 0;
if(h->is_avc) {
if(buf_index >= buf_size) break;
nalsize = 0;
for(i = 0; i < h->nal_length_size; i++)
nalsize = (nalsize << 8) | buf[buf_index++];
} else {
// start code prefix search
for(; buf_index + 3 < buf_size; buf_index++){
// this should allways succeed in the first iteration
......@@ -5612,6 +5637,7 @@ static int decode_nal_units(H264Context *h, uint8_t *buf, int buf_size){
if(buf_index+3 >= buf_size) break;
buf_index+=3;
}
ptr= decode_nal(h, buf + buf_index, &dst_length, &consumed, buf_size - buf_index);
if(ptr[dst_length - 1] == 0) dst_length--;
......@@ -5621,6 +5647,9 @@ static int decode_nal_units(H264Context *h, uint8_t *buf, int buf_size){
av_log(h->s.avctx, AV_LOG_DEBUG, "NAL %d at %d length %d\n", h->nal_unit_type, buf_index, dst_length);
}
if (h->is_avc && (nalsize != consumed))
av_log(h->s.avctx, AV_LOG_ERROR, "AVC: Consumed only %d bytes instead of %d\n", consumed, nalsize);
buf_index += consumed;
if( s->hurry_up == 1 && h->nal_ref_idc == 0 )
......@@ -5750,7 +5779,48 @@ static int decode_frame(AVCodecContext *avctx,
//printf("next:%d buf_size:%d last_index:%d\n", next, buf_size, s->parse_context.last_index);
}
if(s->avctx->extradata_size && s->picture_number==0){
if(h->is_avc && !h->got_avcC) {
int i, cnt, nalsize;
unsigned char *p = avctx->extradata;
if(avctx->extradata_size < 7) {
av_log(avctx, AV_LOG_ERROR, "avcC too short\n");
return -1;
}
if(*p != 1) {
av_log(avctx, AV_LOG_ERROR, "Unknown avcC version %d\n", *p);
return -1;
}
/* sps and pps in the avcC always have length coded with 2 bytes,
so put a fake nal_length_size = 2 while parsing them */
h->nal_length_size = 2;
// Decode sps from avcC
cnt = *(p+5) & 0x1f; // Number of sps
p += 6;
for (i = 0; i < cnt; i++) {
nalsize = BE_16(p) + 2;
if(decode_nal_units(h, p, nalsize) != nalsize) {
av_log(avctx, AV_LOG_ERROR, "Decoding sps %d from avcC failed\n", i);
return -1;
}
p += nalsize;
}
// Decode pps from avcC
cnt = *(p++); // Number of pps
for (i = 0; i < cnt; i++) {
nalsize = BE_16(p) + 2;
if(decode_nal_units(h, p, nalsize) != nalsize) {
av_log(avctx, AV_LOG_ERROR, "Decoding pps %d from avcC failed\n", i);
return -1;
}
p += nalsize;
}
// Now store right nal length size, that will be use to parse all other nals
h->nal_length_size = ((*(((char*)(avctx->extradata))+4))&0x03)+1;
// Do not reparse avcC
h->got_avcC = 1;
}
if(!h->is_avc && s->avctx->extradata_size && s->picture_number==0){
if(0 < decode_nal_units(h, s->avctx->extradata, s->avctx->extradata_size) )
return -1;
}
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment