FFmpeg

Commit Graph

Author	SHA1	Message	Date
Andreas Rheinhardt	4ebfc13c33	avformat/matroskaenc: Don't ignore tags of chapters written late The Matroska muxer writes the Chapters early when chapters were already available when writing the header; in this case any tags pertaining to these chapters get written, too. Yet if no chapters had been supplied before writing the header, Chapters can also be written when writing the trailer if any are supplied. Tags belonging to these chapters were up until now completely ignored. This commit changes this: Writing the tags belonging to chapters has been moved to mkv_write_chapters(). If mkv_write_tags() has not been called yet (i.e. when chapters are written when writing the header), the AVIOContext for writing the ordinary Tags element is used, but not output, as this is left to mkv_write_tags() in order to only write one Tags element. Yet if mkv_write_tags() has already been called, mkv_write_chapters() will output a Tags element of its own which only contains the tags for chapters. When chapters are available initially, the corresponding tags will now be the first tags in the Tags element; but the ordering of tags in Tags is irrelevant anyway. This commit also makes chapter_id_offset local to mkv_write_chapters() as it is used only there and not reused at all. Potentially writing a second Tags element means that the maximum number of SeekHead entries had to be incremented. All the changes to FATE result from the ensuing increase in the amount of space reserved for the SeekHead (21 bytes more). Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	5 years ago
Andreas Rheinhardt	81e39cf481	avformat/matroskaenc: Don't reserve space for duration when unseekable We won't be able to seek back to write the actual duration anyway. FATE-tests using the md5pipe command had to be updated due to this change. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	5 years ago
Andreas Rheinhardt	ccadd00a4a	avformat/matroskaenc: Make output more deterministic Using random values for TrackUID and FileUID (as happens when the AVFMT_FLAG_BITEXACT flag is not set) has the obvious downside of making the output indeterministic. This commit mitigates this by writing the potentially random values with a fixed size of eight byte, even if their actual values would fit into less than eight bytes. This ensures that even in non-bitexact mode, the differences between two files generated with the same settings are restricted to a few bytes in the header. (Namely the SegmentUID, the TrackUIDs (in Tracks as well as when referencing them via TagTrackUID), the FileUIDs (in Attachments as well as in TagAttachmentUID) as well as the CRC-32 checksums of the Info, Tracks, Attachments and Tags level-1-elements.) Without this patch, there might be an offset/a size difference between two such files. The FATE-tests had to be updated because the fixed-sized UIDs are also used in bitexact mode. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	5 years ago
Andreas Rheinhardt	dc2f6b54ac	avformat/matroskaenc: Avoid allocations for SeekHead Up until `e7ddafd5`, the Matroska muxer wrote two SeekHeads: One at the beginning referencing the main level 1 elements (i.e. not the Clusters) and one at the end, referencing the Clusters. This second SeekHead was useless and has therefore been removed. Yet the SeekHead-related functions and structures are still geared towards this usecase: They are built around an allocated array of variable size that gets reallocated every time an element is added to it although the maximum number of Seek entries is a small compile-time constant, so that one should rather include the array in the SeekHead structure itself; and said structure should be contained in the MatroskaMuxContext instead of being allocated separately. The earlier code reserved space for a SeekHead with 10 entries, although we currently write at most 6. Reducing said number implied that every Matroska/Webm file will be 84 bytes smaller and required to adapt several FATE tests; furthermore, the reserved amount overestimated the amount needed for for the SeekHead's length field and how many bytes need to be reserved to write a EBML Void element, bringing the total reduction to 89 bytes. This also fixes a potential segfault: If !mkv->is_live and if the AVIOContext is initially unseekable when writing the header, the SeekHead is already written when writing the header and this used to free the SeekHead-related structures that have been allocated. But if the AVIOContext happens to be seekable when writing the trailer, it will be attempted to write the SeekHead again which will lead to segfaults because the corresponding structures have already been freed. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	5 years ago
Andreas Rheinhardt	0b61ddb576	avformat/matroskaenc: Don't waste bytes writing level 1 elements Up until now, the length field of most level 1 elements has been written using eight bytes, although it is known in advance how much space the content of said elements will take up so that it would be possible to determine the minimal amount of bytes for the length field. This commit changes this. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> Signed-off-by: James Almer <jamrial@gmail.com>	6 years ago
Andreas Rheinhardt	add68dcca9	avformat/matroskaenc: Write CRC-32 in non-seekable mode Given that in both the seekable as well as the non-seekable mode dynamic buffers are used to write level 1 elements and that now no seeks are used in the seekable case any more, the two modes can be combined; as a consequence, the non-seekable mode automatically inherits the ability to write CRC-32 elements. There are no differences in case the output is seekable; when it is not and writing CRC-32 elements is disabled, there can still be minor differences because before this commit, the EBML ID and length field were counted towards the cluster size limit; now they no longer are. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> Signed-off-by: James Almer <jamrial@gmail.com>	6 years ago
Andreas Rheinhardt	4e6df068b5	avformat/matroskaenc: Don't waste bytes in EBML Header Up until now the EBML Header length field has been written with eight bytes, although the EBML Header is always so small that only one byte is needed for it. This patch saves seven bytes for every Matroska/Webm file. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> Signed-off-by: James Almer <jamrial@gmail.com>	6 years ago
James Almer	3b189fae73	avformat/matroskaenc: write a CRC32 element on SeekHead Implements part of ticket #4347 Tested-by: Dave Rice <dave@dericed.com> Tested-by: Jerome Martinez <jerome@mediaarea.net> Reviewed-by: Michael Niedermayer <michael@niedermayer.cc> Signed-off-by: James Almer <jamrial@gmail.com>	8 years ago
James Almer	b33369b612	avformat/matroskaenc: don't reserve space for stream duration tags if the output is not seekable The durations are never written in that situation. Reviewed-by: Michael Niedermayer <michael@niedermayer.cc> Signed-off-by: James Almer <jamrial@gmail.com>	8 years ago
Sasi Inguva	31852540d4	libavformat/matroska: Write stream durations in metadata, in the format of mkvmerge. Compute individual stream durations in matroska muxer. Write them as string tags in the same format as mkvmerge tool does. Signed-off-by: Sasi Inguva <isasi@google.com>	9 years ago
Clément Bœsch	b60c445965	tests: add some ASS/SSA/MKS remux and transcode tests	10 years ago

11 Commits (9b57d2f0a967195dc1c72fda8f3a983a0132a243)