Signed-off-by: Michael Niedermayer <michaelni@gmx.at> --- docs/nut.txt | 116 ++++++++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 88 insertions(+), 28 deletions(-) diff --git a/docs/nut.txt b/docs/nut.txt index 7969e3c..4a2f2b7 100644 --- a/docs/nut.txt +++ b/docs/nut.txt @@ -1,5 +1,5 @@ ================================== -NUT Open Container Format 20080202 +NUT Open Container Format 20130327 ================================== @@ -255,6 +255,7 @@ main_header: tmp_stream=0 tmp_match=1-(1<<62) tmp_head_idx= 0; + tmp_sm_size = 0; for(i=0; i<256; ){ tmp_flag v tmp_fields v @@ -269,7 +270,8 @@ main_header: else count= tmp_mul - tmp_size if(tmp_fields>6) tmp_match s if(tmp_fields>7) tmp_head_idx v - for(j=8; j<tmp_fields; j++){ + if(tmp_fields>8) tmp_sm_size v + for(j=9; j<tmp_fields; j++){ tmp_reserved[i] v } for(j=0; j<count && i<256; j++, i++){ @@ -286,6 +288,7 @@ main_header: reserved_count[i]= tmp_res; match_time_delta[i]= tmp_match; header_idx[i]= tmp_head_idx; + sm_data_size[i]= tmp_sm_size; } } header_count_minus1 v @@ -344,13 +347,55 @@ frame: } if(frame_flags&FLAG_RESERVED) frame_res v - for(i=0; i<frame_res; i++) + if(frame_flags&FLAG_SM_DATA) + sm_data_size v + for(i=0; i<frame_res - !(frame_flags&FLAG_SM_DATA); i++) reserved v if(frame_flags&FLAG_CHECKSUM){ checksum u(32) } data +data: + frame_data + if (sm_data_size>0) { + side_data + meta_data + } + +side_data + sm_data + +meta_data + sm_data + +sm_data: + count v + for(i=0; i<count; i++){ + name vb + value s + if (value==-1){ + type= "UTF-8" + value vb + }else if (value==-2){ + type vb + value vb + }else if (value==-3){ + type= "s" + value s + }else if (value==-4){ + type= "t" + value t + }else if (value<-4){ + type= "r" + value.den= -value-4 + value.num s + }else{ + type= "v" + } + } + + index: max_pts t syncpoints v @@ -399,30 +444,7 @@ info_packet: until 2006-11-04.) chapter_start t chapter_len v - count v - for(i=0; i<count; i++){ - name vb - value s - if (value==-1){ - type= "UTF-8" - value vb - }else if (value==-2){ - type vb - value vb - }else if (value==-3){ - type= "s" - value s - }else if (value==-4){ - type= "t" - value t - }else if (value<-4){ - type= "r" - value.den= -value-4 - value.num s - }else{ - type= "v" - } - } + meta_data reserved_bytes syncpoint: @@ -643,6 +665,7 @@ flags[frame_code], frame_flags (v) otherwise data_size_msb is 0. 6 FLAG_CHECKSUM If set, the frame header contains a checksum. 7 FLAG_RESERVED If set, reserved_count is coded in the frame header. + 8 FLAG_SM_DATA If set, sm_data_size is coded in the frame header. 10 FLAG_HEADER_IDX If set, header_idx is coded in the frame header. 11 FLAG_MATCH_TIME If set, match_time_delta is coded in the frame header @@ -690,7 +713,44 @@ pts_delta[frame_code] (s) MUST be <16384 and >-16384. reserved_count[frame_code] (v) - MUST be <256. + Muxers supporting FLAG_SM_DATA MUST set the reserved_count to 1 + if side data is in use in order to be compatible with older demuxers + Demuxers MUST support any value from 0 to 255. + +sidedata_size[frame_code] (v) + Size in bytes at the end inside data which represent frame sidedata and + frame metadata. + +sm_data / side_data / meta_data + This data structure is used both in frames for per frame side and metadata + as well as info tags for metadata covering the whole file, a stream + chapter or other. + Metadata is data that is about the actual data and generally not essential + for correct presentation + Sidedata is semantically part of the data and essential for its correct + presentation. The same syntax is used by both for simplicity. + Types of per frame side data: + "Channels", "ChannelLayout", "SampleRate", "Width", "Height" + This frame changes the number of channels, the channel layout, ... to + the given value (v) + If used in any frame of a stream then every keyframe of the stream + SHOULD carry such sidedata to allow seeking. + "Extradata", "Palette" + This frame changes the codec_specific_data or palette to the given + value (vb) + If used in any frame of a stream then every keyframe of the stream + SHOULD carry such sidedata to allow seeking. + "CodecSpecificSide<num>" + Codec specific side data, equivalent to matroskas BlockAdditional (vb) + the "<num>" should be replaced by a number identifying the type of + side data, it is equivalent/equal to BlockAddId in matroska. + "SkipStart", "SkipEnd" + The decoder should skip/drop the specified number of samples at the + start/end of this frame (v) + "UserData<identifer here>" + User specific side data, the "<identifer here>" should be replaced + by a globally unique identifer of the project that + uses/creates/understands the side data. For example "UserDataFFmpeg" data_size data_size = data_size_lsb + data_size_msb * data_size_mul ; -- 1.7.9.5