This commit switches off forced correct nesting of tags and only keeps
it for font tags. See long explanations in the code for the rationale.
This results in various FATE changes which I'll explain here:
- various swapping in font attributes, this is mostly noise due to the
old reverse stack way of printing them. The new one is more correct as
the last attribute takes over the previous ones.
- unrecognized tags disappears
- invalid tags that were previously displayed aren't anymore (instead,
we have a warning). This is better for the end user
The main benefit of this commit is to be more tolerant to error, leading
to a better handling of badly nested tags or random wrong formatting for
the end user.
This reduces the number of strstr() calls per byte
This diasalows empty tags like '< >' as well as '<' in tags like '<ab<cd<<ef>'
Fixes timeout
Fixes: 1817/clusterfuzz-testcase-minimized-5104230530547712
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Some .srt files use this tag.
(An alternative implementation would be correctly ignoring unknown tags,
and treating them as whitespace. libass can do automatic line wrapping.)
This reduces the worst case from O(n²) to O(n) time
Fixes Timeout
Fixes: 2127/clusterfuzz-testcase-minimized-6595787859427328
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes out of array access
Fixes: 1354/clusterfuzz-testcase-minimized-5520132195483648
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The positioning was completely wrong. First, the coordinates are
expressed in ASS playback resolution (which is by default 384x288).
Secondly, the coordinates define a drawing rectangle, not a moving area.
The previous code was making subtitles move from a random position to
another random position.
Here we rescale assuming the video resolution is a DVD one (720x480). We
can't really do anything better so far, but since this positioning
information is often from a DVD rip we can consider them relatively
safe.
The SRT format should never have outputted CODEC_ID_SRT packets in the
first place: SRT is a subtitle format containing SubRip text markup
events. The timing information is part of the format, not the codec, and
thus CODEC_ID_SRT should not exist.
Creating packets with the timing information within the payload only
leads to problem (such as remuxing with timing alteration not working),
especially when the SubRip markup is being used in container like
Matroska in addition to this standalone SRT format.
The main reason the timing line was included in those CODEC_ID_SRT
packets is likely because it contained extra information (the event
position) the codec actually needs. This issue is solved by using the
AV_PKT_DATA_SUBTITLE_POSITION side data type.
After various discussions, we concluded that, amongst other things,
it made sense to have a separate subrip decoder that did not use
in-band timing information, and rather relied on the ffmpeg level
timing.
As this is 90% the same as the existing srt decoder, it's implemented
in the same file.
Signed-off-by: Philip Langdale <philipl@overt.org>
Call this new function before decode() to replace the custom and
inconsistant initialization in various decoders.
This function is equivalent to avcodec_get_frame_defaults() for AVFrame.
Signed-off-by: Aurelien Jacobs <aurel@gnuage.org>
It is pretty hopeless that other considerable projects will adopt
libavutil alone in other projects. Projects that need small footprint
are better off with more specialized libraries such as gnulib or rather
just copy the necessary parts that they need. With this in mind, nobody
is helped by having libavutil and libavcore split. In order to ease
maintenance inside and around FFmpeg and to reduce confusion where to
put common code, avcore's functionality is merged (back) to avutil.
Signed-off-by: Reinhard Tartler <siretart@tauware.de>
None of these symbols should be accessed directly, so declare them as
hidden.
Signed-off-by: Mans Rullgard <mans@mansr.com>
(cherry picked from commit d36beb3f69)
Michael Niedermayer
Kevin Backhouse via RT
James Almer
Clément Bœsch
DongHoon Kang
wm4
Rodger Combs
Yayoi
Diego Biurrun
Clément Bœsch
Paul B Mahol
Michael Niedermayer
Philip Langdale
Martin Storsjö
Anton Khirnov
Fabian Greffrath
Aurelien Jacobs
Mans Rullgard
Reinhard Tartler
Diego Elio Pettenò