Currently, we have a AV_CODEC_ID_SSA, which matches the way the ASS/SSA
markup is muxed in a standalone .ass/.ssa file. This means the AVPacket
data starts with a "Dialogue:" string, followed by a timing information
(start and end of the event as string) and a trailing CRLF after each
line. One packet can contain several lines. We'll refer to this layout
as "SSA" or "SSA lines".
In matroska, this markup is not stored as such: it has no "Dialogue:"
prefix, it contains a ReadOrder field, the timing information is not in
the payload, and it doesn't contain the trailing CRLF. See [1] for more
info. We'll refer to this layout as "ASS".
Since we have only one common codec for both formats, the matroska
demuxer is constructing an AVPacket following the "SSA lines" format.
This causes several problems, so it was decided to change this into
clean ASS packets.
Some insight about what is changed or unchanged in this commit:
CODECS
------
- the decoding process still writes "SSA lines" markup inside the ass
fields of the subtitles rectangles (sub->rects[n]->ass), which is
still the current common way of representing decoded subtitles
markup. It is meant to change later.
- new ASS codec id: AV_CODEC_ID_ASS (which is different from the
legacy AV_CODEC_ID_SSA)
- lavc/assdec: the "ass" decoder is renamed into "ssa" (instead of
"ass") for consistency with the codec id and allows to add a real
ass decoder. This ass decoder receives clean ASS lines (so it starts
with a ReadOrder, is followed by the Layer, etc). We make sure this
is decoded properly in a new ass-line rectangle of the decoded
subtitles (the ssa decoder OTOH is doing a simple straightforward
copy). Using the packet timing instead of data string makes sure the
ass-line now contains the appropriate timing.
- lavc/assenc: just like the ass decoder, the "ssa" encoder is renamed
into "ssa" (instead of "ass") for consistency with the codec id, and
allows to add a real "ass" encoder.
One important thing about this encoder is that it only supports one
ass rectangle: we could have put several dialogue events in the
AVPacket (separated by a \0 for instance) but this would have cause
trouble for the muxer which needs not only the start time, but also
the duration: typically, you have merged events with the same start
time (stored in the AVPacket->pts) but a different duration. At the
moment, only the matroska do the merge with the SSA-line codec.
We will need to make sure all the decoders in the future can't add
more than one rectangle (and only one Dialogue line in it
obviously).
FORMATS
-------
- lavf/assenc: the .ass/.ssa muxer can take both SSA and ASS packets.
In the case of ASS packets as input, it adds the timing based on the
AVPacket pts and duration, and mux it with "Dialogue:", trailing
CRLF, etc.
- lavf/assdec: unchanged; it currently still only outputs SSA-lines
packets.
- lavf/mkv: the demuxer can now output ASS packets without the need of
any "SSA-lines" reconstruction hack. It will become the default at
next libavformat bump, and the SSA support will be dropped from the
demuxer. The muxer can take ASS packets since it's muxed normally,
and still supports the old SSA packets. All the SSA support and
hacks in Matroska code will be dropped at next lavf bump.
[1]: http://www.matroska.org/technical/specs/subtitles/ssa.html
Using the first names of authors sounds somewhat unprofessional
and might be considered offensive which is not intended.
The new names use the initials of the authors due to simplicity
and the possibility to apply it consistently without the need
to find political correct names for each future case where
alternative codecs might exist. Also its shorter ...
If someone has a better idea, like maybe 2 random letters
and people prefer it then iam happy to switch to that ...
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
* commit '8a776ad90e00ab2b98e8683ac6182d641a383c3a':
h261: Move shared data tables from a header to a proper C file
Conflicts:
libavcodec/Makefile
libavcodec/h261data.c
libavcodec/h261dec.c
libavcodec/h261enc.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit 'b4d24b471bc52f1f78a43ee330199e70483e51c3':
build: Remove configure-generated .config file on distclean
msmpeg4: Split decoding related functions to a separate file
Conflicts:
Makefile
libavcodec/Makefile
libavcodec/msmpeg4.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '1b6d66745ac1768adb387c2227cdcf4452271149':
Split MPEG-1/2 decoder code off from MPEG-1/2 common code
Conflicts:
libavcodec/Makefile
libavcodec/mpeg12.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '1db6a080bddd14fed6b29140ecd2e21e42b1c022':
dca: Move ff_dca_convert_bitstream() to the DCA common code
vdpau: wrap codec specific functions in appropiate #ifs
Conflicts:
libavcodec/Makefile
Merged-by: Michael Niedermayer <michaelni@gmx.at>
This fixes standalone compilation of the msmpeg4v2, msmpeg4v3
and wmv2 encoders, that previously failed to link due to the
decoder codepaths requiring error_resilience.
Signed-off-by: Martin Storsjö <martin@martin.st>
The two types of packets (PCI and DSI) are passed untouched but combined by the new codec ID AV_CODEC_ID_DVD_NAV.
The first 980 bytes in the packet contain the PCI data. The next 1018 are the DSI data.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Only compile if CONFIG_ENCODERS is enabled, i.e. if at least one
encoder is to be compiled. This prevents it from being includes in
a decoder-only build.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This reverts commit d3edc65dd1, reversing
changes made to 150de78d7c.
Conflicts:
libavcodec/version.h
It seems there are several applications still using it
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
The sh4 optimizations are removed, because the code is
100% identical to the C code, so it is unlikely to
provide any real practical benefit.
Signed-off-by: Diego Biurrun <diego@biurrun.de>
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
* commit 'e6bc38fd49c94726b45d5d5cc2b756ad8ec49ee0':
wmv2: move IDCT to its own DSP context.
Conflicts:
libavcodec/dsputil.h
tests/ref/seek/vsynth2-wmv2
tests/ref/vsynth/vsynth1-wmv2
tests/ref/vsynth/vsynth2-wmv2
Merged-by: Michael Niedermayer <michaelni@gmx.at>
This allows us to remove FF_IDCT_WMV2, which serves no practical purpose
other than to be able to select the WMV2 IDCT for MPEG (or vice versa)
and get corrupt output.
Fate tests for all wmv2-related tests change, because (for some obscure
reason) they forced use of the MPEG IDCT. You would get the same changes
previously by not using -idct simple in the fate test (or replacing it
with -idct auto).
* commit '3f111804eb5c603a344706b84b7164cbf7b4e0df':
libvpx: make vp8 and vp9 selectable
libvpx: support vp9
nut: support vp9 tag
mkv: support vp9 tag
rtpdec: Make variables that should wrap unsigned
Conflicts:
configure
libavcodec/Makefile
libavcodec/allcodecs.c
libavcodec/avcodec.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit 'ba0c72a9ae1e2954e5dcf920f7b4e9a8f8a22f3e':
build: Remove stray Makefile entry for non-existent VCR1 encoder
rtpdec: Handle more received packets than expected when sending RR
Merged-by: Michael Niedermayer <michaelni@gmx.at>
