Adding early support for a subset of the proposed colour elements
according to the latest version of spec:
https://mailarchive.ietf.org/arch/search/?email_list=cellar&gbt=1&index=hIKLhMdgTMTEwUTeA4ct38h0tmE
Like matroskadec, I've left out elements for pix_fmt related things
as there still seems to be some discussion around these.
The new elements are exposed under strict experimental mode.
Signed-off-by: Neil Birkbeck <neil.birkbeck@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Currently, AVStream contains an embedded AVCodecContext instance, which
is used by demuxers to export stream parameters to the caller and by
muxers to receive stream parameters from the caller. It is also used
internally as the codec context that is passed to parsers.
In addition, it is also widely used by the callers as the decoding (when
demuxer) or encoding (when muxing) context, though this has been
officially discouraged since Libav 11.
There are multiple important problems with this approach:
- the fields in AVCodecContext are in general one of
* stream parameters
* codec options
* codec state
However, it's not clear which ones are which. It is consequently
unclear which fields are a demuxer allowed to set or a muxer allowed to
read. This leads to erratic behaviour depending on whether decoding or
encoding is being performed or not (and whether it uses the AVStream
embedded codec context).
- various synchronization issues arising from the fact that the same
context is used by several different APIs (muxers/demuxers,
parsers, bitstream filters and encoders/decoders) simultaneously, with
there being no clear rules for who can modify what and the different
processes being typically delayed with respect to each other.
- avformat_find_stream_info() making it necessary to support opening
and closing a single codec context multiple times, thus
complicating the semantics of freeing various allocated objects in the
codec context.
Those problems are resolved by replacing the AVStream embedded codec
context with a newly added AVCodecParameters instance, which stores only
the stream parameters exported by the demuxers or read by the muxers.
"language" is not an offical matroska tag.
Track languages are specified with the MATROSKA_ID_TRACKLANGUAGE ebml.
Writing the tag overrides the ebml specified language during playback with
libav and some other players.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Note that convergence_duration had another meaning, one which was in
practice never used. The only real use for it was a 64 bit replacement
for the duration field. It's better just to make duration 64 bits, and
to get rid of it.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
And update the preference for the newer codecs now that the libraries
seem stable and widespread enough.
Bug-Id: 695
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
Fixing small leaks that can occur when mkv_write_tracks fails in mkv_write_header
(e.g., if video track has unknown codec). Also changing mkv_write_seekhead to take
the MatroskaMuxContext to avoid having dangling pointers.
Signed-off-by: Neil Birkbeck <neil.birkbeck@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
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>
Per matroska Block Structure [1], for keyframes 0th bit of the flag
should not be set (unlike SimpleBlocks). For Blocks, keyframes is
inferred by the absence of ReferenceBlock element (as done by
matroskadec). This CL writes the flag correctly and inserts the
ReferenceBlock element for non-keyframes. The timestamp inserted is
that of the immediately preceding frame (which is true for VP8 and VP9
- the only 2 codecs using the matroska block element as of now). It
also considers all non-video frames (audio, subtitles, metadata) to
be keyframes.
[1] http://www.matroska.org/technical/specs/index.html#block_structure
Signed-off-by: Vignesh Venkatasubramanian <vigneshv@google.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Generally, libavformat exports cover art pictures as video streams with
1 packet and AV_DISPOSITION_ATTACHED_PIC set. Only matroskadec exported
it as attachment with codec_id set to AV_CODEC_ID_MJPEG.
Obviously, this should be consistent, so change the Matroska demuxer to
export a AV_DISPOSITION_ATTACHED_PIC pseudo video stream.
Matroska muxing is probably incorrect too. I know that it can create
broken files with an audio track and just 1 video frame when e.g.
remuxing mp3 with APIC to mkv. But for now this commit does not change
anything about muxing, and also continues to write attachments with
AV_CODEC_ID_MJPEG should the muxer application have special knowledge
that the Matroska is broken in this way.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
This patch adds support for WebM Live Muxing by adding a new WebM
Chunk muxer. It writes out live WebM Chunks which can be used for
playback using Live DASH Clients.
Please see muxers.texi for sample usage.
Signed-off-by: Vignesh Venkatasubramanian <vigneshv@google.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Generally, libavformat exports cover art pictures as video streams with
1 packet and AV_DISPOSITION_ATTACHED_PIC set. Only matroskadec exported
it as attachment with codec_id set to AV_CODEC_ID_MJPEG.
Obviously, this should be consistent, so change the Matroska demuxer to
export a AV_DISPOSITION_ATTACHED_PIC pseudo video stream.
Matroska muxing is probably incorrect too. I know that it can create
broken files with an audio track and just 1 video frame when e.g.
remuxing mp3 with APIC to mkv. But for now this commit does not change
anything about muxing, and also continues to write attachments with
AV_CODEC_ID_MJPEG should the muxer application have special knowledge
that the Matroska is broken in this way.
Fixes trac #4423.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
should be the raw amount of pixels (for example 3840x1080 for full HD side by
side) and the DisplayWidth/Height in pixels should be the amount of pixels for
one plane (1920x1080 for that full HD stream)."
So, move the aspect ratio check in the mkv_write_stereo_mode() function
and always write the embl when stereo format and/or aspect ration is set.
Also add a few comments to that function.
CC: libav-stable@libav.org
Found-by: Asan Usipov <asan.usipov@gmail.com>
Michael Niedermayer
Luca Barbato
Neil Birkbeck
Hendrik Leppkes
Ronald S. Bultje
Anton Khirnov
Marton Balint
Carl Eugen Hoyos
Rodger Combs
Clément Bœsch
John Stebbins
wm4
Timothy Gu
Sasi Inguva
Vignesh Venkatasubramanian
Michael Niedermayer
Vittorio Giovara
Diego Biurrun