diff options
| -rw-r--r-- | DOCS/tech/mpcf.txt | 62 |
1 files changed, 42 insertions, 20 deletions
diff --git a/DOCS/tech/mpcf.txt b/DOCS/tech/mpcf.txt index d7cf7c78dc..58c2368c85 100644 --- a/DOCS/tech/mpcf.txt +++ b/DOCS/tech/mpcf.txt @@ -1,5 +1,5 @@ ======================================== -NUT Open Container Format DRAFT 20060105 +NUT Open Container Format DRAFT 20060120 ======================================== @@ -131,23 +131,29 @@ main header: stream_count v max_distance v max_index_distance v + tmp_pts=0 + tmp_mul=1 + tmp_stream=0 for(i=0; i<256; ){ tmp_flag v tmp_fields v - if(tmp_fields>0) tmp_pts s - if(tmp_fields>1) tmp_mul v - if(tmp_fields>2) tmp_stream v - if(tmp_fields>3) tmp_size v + if(tmp_fields>0) tmp_sflag v + else tmp_sflag=0 + if(tmp_fields>1) tmp_pts s + if(tmp_fields>2) tmp_mul v + if(tmp_fields>3) tmp_stream v + if(tmp_fields>4) tmp_size v else tmp_size=0 - if(tmp_fields>4) tmp_res v + if(tmp_fields>5) tmp_res v else tmp_res=0 - if(tmp_fields>5) count v + if(tmp_fields>6) count v else count= tmp_mul - tmp_size - for(j=6; j<tmp_fields; j++){ + for(j=7; j<tmp_fields; j++){ tmp_reserved[i] v } for(j=0; j<count && i<256; j++, i++){ flags[i]= tmp_flag; + stream_flags[i]= tmp_sflag; stream_id_plus1[i]= tmp_stream; data_size_mul[i]= tmp_mul; data_size_lsb[i]= tmp_size + j; @@ -208,6 +214,9 @@ frame: if(flags[frame_code]&1){ data_size_msb v } + if(flags[frame_code]&2){ + coded_stream_flags v + } for(i=0; i<reserved_count[frame_code]; i++) reserved v data @@ -302,6 +311,8 @@ back_ptr one keyframe for each stream lies between the syncpoint to which real_back_ptr points, and the current syncpoint. + A stream where EOR is set is to be ignored for back_ptr. + global_key_pts After a syncpoint, last_pts of each stream is to be set to: last_pts[i] = convert_ts(global_key_pts, timebase[stream], timebase[i]) @@ -417,17 +428,27 @@ frame_code different from the first byte of any startcode flags[frame_code] - first of the flags from MSB to LSB are called KD - if D is 1 then data_size_msb is coded, otherwise data_size_msb is 0 - K is the keyframe_type - 0 -> no keyframe, - 1 -> keyframe, - flags=4 can be used to mark illegal frame_code bytes - frame_code=78 must have flags=4 - Note: frames MUST NOT depend(1) upon frames prior to the last - frame_startcode - Important: depend(1) means dependency on the container level (NUT) not - dependency on the codec level + Bit Name Description + 1 data_size_msb if set, data_size_msb is at frame header, + otherwise data_size_msb is 0 + 2 more_flags if set, stream control flags are at frame header. + 4 invalid if set, frame_code is invalid. + + frame_code=78 ('N') MUST have flags=64 + +stream_flags + stream_flags is "stream_flags[frame_code] ^ coded_stream_flags" + + Bit Name Description + 1 is_key if set, frame is keyframe + 2 end_of_relevance if set, stream has no relevance on + presentation. (EOR) + + EOR frames MUST be zero-length and must be set keyframe. + All streams SHOULD end with EOR, where the pts of the EOR indicates the + end presentation time of the final frame. + An EOR set stream is unset by the first content frames. + When an EOR is unset, dts_cache of the stream is reset to -1. stream_id_plus1[frame_code] must be <250 @@ -476,7 +497,8 @@ dts this buffer is initalized with decode_delay -1 elements Pts of all frames in all streams MUST be bigger or equal to dts of all - previous frames in all streams, compared in common timebase. + previous frames in all streams, compared in common timebase. (EOR + frames are NOT exempt from this rule) width/height MUST be set to the coded width/height |