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ffmpeg
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Elision header demuxing support. 

Originally committed as revision 11935 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2008-02-15 02:36:09 +00:00
parent 880add3743
commit 3b4f69ae8c
2 changed files with 45 additions and 5 deletions
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3
libavformat/nut.h
View File

@ -66,6 +66,7 @@ typedef struct {
uint16_t size_lsb;
int16_t pts_delta;
uint8_t reserved_count;
uint8_t header_idx;
} FrameCode; // maybe s/FrameCode/framecode_t/ or change all to Java style but do not mix
typedef struct {
@ -84,6 +85,8 @@ typedef struct {
// int written_packet_size;
// int64_t packet_start;
FrameCode frame_code[256];
uint8_t header_len[128];
const uint8_t *header[128];
uint64_t next_startcode; ///< stores the next startcode if it has already been parsed but the stream is not seekable
StreamContext *stream;
unsigned int max_distance;

47
libavformat/nutdec.c
View File

@ -184,7 +184,7 @@ static int decode_main_header(NUTContext *nut){
ByteIOContext *bc = s->pb;
uint64_t tmp, end;
unsigned int stream_count;
int i, j, tmp_stream, tmp_mul, tmp_pts, tmp_size, count, tmp_res;
int i, j, tmp_stream, tmp_mul, tmp_pts, tmp_size, count, tmp_res, tmp_head_idx;
int64_t tmp_match;
end= get_packetheader(nut, bc, 1, MAIN_STARTCODE);
@ -214,6 +214,7 @@ static int decode_main_header(NUTContext *nut){
tmp_mul=1;
tmp_stream=0;
tmp_match= 1-(1LL<<62);
tmp_head_idx= 0;
for(i=0; i<256;){
int tmp_flags = ff_get_v(bc);
int tmp_fields= ff_get_v(bc);
@ -227,8 +228,9 @@ static int decode_main_header(NUTContext *nut){
if(tmp_fields>5) count = ff_get_v(bc);
else count = tmp_mul - tmp_size;
if(tmp_fields>6) tmp_match = get_s(bc);
if(tmp_fields>7) tmp_head_idx= ff_get_v(bc);
while(tmp_fields-- > 7)
while(tmp_fields-- > 8)
ff_get_v(bc);
if(count == 0 || i+count > 256){
@ -252,10 +254,28 @@ static int decode_main_header(NUTContext *nut){
nut->frame_code[i].size_mul = tmp_mul ;
nut->frame_code[i].size_lsb = tmp_size+j;
nut->frame_code[i].reserved_count = tmp_res ;
nut->frame_code[i].header_idx = tmp_head_idx;
}
}
assert(nut->frame_code['N'].flags == FLAG_INVALID);
if(end > url_ftell(bc) + 4){
int rem= 1024;
GET_V(nut->header_count, tmp<128U)
nut->header_count++;
for(i=1; i<nut->header_count; i++){
GET_V(nut->header_len[i], tmp>0 && tmp<256);
rem -= nut->header_len[i];
if(rem < 0){
av_log(s, AV_LOG_ERROR, "invalid elision header\n");
return -1;
}
nut->header[i]= av_malloc(nut->header_len[i]);
get_buffer(bc, nut->header[i], nut->header_len[i]);
}
assert(nut->header_len[0]==0);
}
if(skip_reserved(bc, end) || get_checksum(bc)){
av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
return -1;
@ -591,7 +611,7 @@ static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
return 0;
}
static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, int frame_code){
static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, uint8_t *header_idx, int frame_code){
AVFormatContext *s= nut->avf;
ByteIOContext *bc = s->pb;
StreamContext *stc;
@ -609,6 +629,7 @@ static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, in
*stream_id = nut->frame_code[frame_code].stream_id;
pts_delta = nut->frame_code[frame_code].pts_delta;
reserved_count = nut->frame_code[frame_code].reserved_count;
*header_idx = nut->frame_code[frame_code].header_idx;
if(flags & FLAG_INVALID)
return -1;
@ -632,10 +653,21 @@ static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, in
}
if(flags&FLAG_MATCH_TIME)
get_s(bc);
if(flags&FLAG_HEADER_IDX)
*header_idx= ff_get_v(bc);
if(flags&FLAG_RESERVED)
reserved_count= ff_get_v(bc);
for(i=0; i<reserved_count; i++)
ff_get_v(bc);
if(*header_idx >= (unsigned)nut->header_count){
av_log(s, AV_LOG_ERROR, "header_idx invalid\n");
return -1;
}
if(size > 4096)
*header_idx=0;
size -= nut->header_len[*header_idx];
if(flags&FLAG_CHECKSUM){
get_be32(bc); //FIXME check this
}else if(size > 2*nut->max_distance || FFABS(stc->last_pts - *pts) > stc->max_pts_distance){
@ -655,8 +687,9 @@ static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
int size, stream_id, discard;
int64_t pts, last_IP_pts;
StreamContext *stc;
uint8_t header_idx;
size= decode_frame_header(nut, &pts, &stream_id, frame_code);
size= decode_frame_header(nut, &pts, &stream_id, &header_idx, frame_code);
if(size < 0)
return -1;
@ -675,7 +708,11 @@ static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
return 1;
}
av_get_packet(bc, pkt, size);
av_new_packet(pkt, size + nut->header_len[header_idx]);
memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
pkt->pos= url_ftell(bc); //FIXME
get_buffer(bc, pkt->data + nut->header_len[header_idx], size);
pkt->stream_index = stream_id;
if (stc->last_flags & FLAG_KEY)
pkt->flags |= PKT_FLAG_KEY;