In order to represent the codec delay accurately in Matroska, a
new element CodecDelay has been introduced. It contains the
overall delay added by the codec in nanoseconds. This patch adds
support for muxing CodecDelay value in the container.
Matroska spec for CodecDelay element can be found here:
http://matroska.org/technical/specs/index.html#CodecDelay
Signed-off-by: Vignesh Venkatasubramanian <vigneshv@google.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Allow emitting the current cluster that is being written before
starting a new one, simplifying how to figure out where clusters
are positioned in the output stream (for live streaming).
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
Changes since v1 of the patch:
- enable option by default
- add documentation
- move up PTS override code after PES header parsing, to ensure we use the
last PCR before the first packet of the teletext PES packet.
The option overrides teletext packet PTS and DTS values with the timestamps
calculated from the PCR of the first program which the teletext stream is part
of and is not discarded.
Using the same teletext PID for multiple programs is possible, therefore we
need some kind of heuristics to know which program PCR we should synchronize
to. Using the first non-discarded PCR pid among the programs of the teletext
stream seemed like a good choice.
The patch does not do PCR interpolation to estimate the PCR of the teltetext
packet, it just uses the last PCR of the program, which may cause a slight
error (0.1 sec) in the teletext packet pts-es.
Based on a patch by Reimar Döffinger.
http://lists.ffmpeg.org/pipermail/ffmpeg-devel/2012-September/131610.html
Signed-off-by: Marton Balint <cus@passwd.hu>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avconv uses private and internal fields from libavformat, we thus must
match the layout even of the fields marked non public.
Otherwise ffmpegs libavformat could not be used as a dropin replacement
on debian/ubuntu
The current soname of libavformat was not part of any release nor are any
fields marked public moved thus in theory
no installed shared lib ABI breakage should occur. Still the need for this
change is unfortunate and chilling.
If you installed shared libs from a recent development version of libavformat
that is more recent than the last release. You probably want to check or rebuild
applications that linked to it.
minor versions of avformat & avdevice are bumped to allow detecting this
as both use the updated struct
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
The toc is inexact and not using it can thus make sense.
Using it is faster though, thus the opposite can similarly makes sense
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Allow applications to request reading streamcast metadata. This uses
AVOptions as API, and requires the application to explicitly request
and read metadata. Metadata can be updated mid-stream; if an
application is interested in that, it has to poll for the data by
reading the "icy_metadata_packet" option in regular intervals.
There doesn't seem to be a nice way to transfer the metadata in a nicer
way. Converting the metadata to ID3v2 tags might be a nice idea, but
the libavformat mp3 demuxer doesn't seem to read these tags mid-stream,
and even then we couldn't guarantee that tags are not inserted in the
middle of mp3 packet data.
This commit provides the minimum to enable applications to retrieve
this information at all.
Signed-off-by: Stefano Sabatini <stefasab@gmail.com>
There are 4 separate WebVTT text track kinds: subtitles (the default
if not otherwise specified), captions, descriptions, and metadata.
The WebM muxer needs to know which WebVTT text track kind this is, in
order to synthesize the correct track type and codec id.
To allow a demuxer to indicate the text track kind of the input, a new
set of AV_DISPOSITION flag values has been added, corresponding to
each of the non-default text track kind values.
Adding an arbitrary amount of padding bytes at the end of the
ID3 metadata fixes cover art display for some software (iTunes,
Traktor, Serato, Torq).
For reference (ID3 metadata):
[ Apic frames ] -> cover doesn't show up
[ Apic frames, Padding ] -> ok
[ Apic frames, ID3 frames ] -> ok
[ ID3 frames, Apic frames ] -> cover doesn't show up
[ ID3 frames, Apic frames, Padding ] -> ok
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
This reverts commit 6cc12353a8.
Conflicts:
libavformat/version.h
Allowing to automatically select the concat demuxer raises
security concerns, as it allows a possibly hostile file to
access any file on the system. Guessing the format based on
the file name extension does not allow to enable the safe
mode designed to avoid it.
The handling of the environment variable no_proxy, present since
one of the initial commits (de6d9b6404), is inconsistent with
how many other applications and libraries interpret this
variable. Its bare presence does not indicate that the use of
proxies should be skipped, but it is some sort of pattern for
hosts that does not need using a proxy (e.g. for a local network).
As investigated by Rudolf Polzer, different libraries handle this
in different ways, some supporting IP address masks, some supporting
arbitrary globbing using *, some just checking that the pattern matches
the end of the hostname without regard for whether it actually is
the right domain or a domain that ends in the same string.
This simple logic should be pretty similar to the logic used by
lynx and curl.
Signed-off-by: Martin Storsjö <martin@martin.st>
Expose the current sequence number via an AVOption - this can
be used both for setting the initial sequence number, or for
querying the current number.
Signed-off-by: Martin Storsjö <martin@martin.st>
Paul B Mahol
Vignesh Venkatasubramanian
Clément Bœsch
Dirk Farin
Michael Niedermayer
Stefano Sabatini
Martin Storsjö
Alexis Ballier
Marton Balint
Andrey Utkin
Gavriloaie Eugen-Andrei
Carl Eugen Hoyos
wm4
Matthew Heaney
James Almer
Matthieu Bouron
Anton Khirnov
Nicolas George
Clément Bœsch
Daniel Verkamp
Micah Galizia