ff_slice_thread_init() uses a static variable to hold a function
pointer, although the value of said pointer needn't be saved between
different runs of this function at all.
The reason for this being so is probably that said pointer points to
a static function (if used); but storage class specifiers like "static"
are not part of the type of an object and so including it in the pointer
declaration is wrong (anyway, "static" means different things in both
contexts: for the function declaration it affects linkage, for the
variable storage duration).
Using a static variable here can lead to races, e.g. when initializing
VP9 (for which said function pointer was added) and H.264 with slice
threading. The latter has the FF_CODEC_CAP_INIT_THREADSAFE flag set and
is therefore unaffected by the lock guarding initializations of
decoders.
Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Using MPEG-2 intra VLC tables is spec-incompliant for MPEG-1 and given
that an MPEG-1 bitstream can't signal whether MPEG-2 intra VLC tables
have been used the output is broken. Therefore this option is removed
immediately without any deprecation period.
Reviewed-by: James Almer <jamrial@gmail.com>
Reviewed-by: Marton Balint <cus@passwd.hu>
Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
They are not always coded in the bistream for each frame. In some cases, the
values need to be taken from a reference frame.
See section 6.8.20 from the AV1 spec.
Signed-off-by: James Almer <jamrial@gmail.com>
This reverts commit f9eec62983.
This does not effectively cover all cases. The values for some frames need
to be inferred by the decoder.
Signed-off-by: James Almer <jamrial@gmail.com>
The max depth is 16bps, the max allowed coefficient depth is depth+6
Fixes: signed integer overflow: 1074266112 + 1073725439 cannot be represented in type 'int'
Fixes: 26493/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HEVC_fuzzer-5657763331702784
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This avoids per codec checks for channels not being 0
Fixes: division by 0
Fixes: 25419/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FASTAUDIO_fuzzer-5632544761184256
Fixes: 25433/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FASTAUDIO_fuzzer-6215671900536832
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Suggested-by: Paul B Mahol <onemda@gmail.com>
See: [FFmpeg-devel] [PATCH 1/3] avcodec/fastaudio: Check channel
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
They add considerable complexity to frame-threading implementation,
which includes an unavoidably leaking error path, while the advantages
of this option to the users are highly dubious.
It should be always possible and desirable for the callers to make their
get_buffer2() implementation thread-safe, so deprecate this option.
This patch is relatively straightforward with one exception:
the decoder option flag.
The option was introduced to troubleshoot but its existence is conflicting
and redundant now that we have a codec-generic flag.
Hence this patch deprecates it.
The way it interacts with AV_CODEC_EXPORT_DATA_FILM_GRAIN is as follows:
If filmgrain is unset and AV_CODEC_EXPORT_DATA_FILM_GRAIN is
present, disable film grain application and export side data.
If filmgrain is set to 0, disable film grain and export side data.
If filmgrain is set to 1, apply film grain but export side data if
the AV_CODEC_EXPORT_DATA_FILM_GRAIN flag is set. This may result in
double film grain application, but the user has requested it by setting
both.
The MPEG-1/2 encoders initialize several tables once during the first
time one of the encoders is initialized; the table for MPEG-2 intra VLC
lengths is only initialized if it is used for this encoder instance.
This implies that if the first MPEG-1/2 encoder to be initialized does
not use it, it will never be initialized even if a later encoder
instance makes use of them. Fix this by initializing this table
unconditionally.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This table is currently initialized up to three times: Once by the
encoder and twice by the decoders (once by the fixed and once by the
floating-point decoder); each of these initializations is guarded by an
AVOnce, yet the fact that there are three of them implies that there
might be data races (the fact that each entry is only written to once
(to its final value) when initializing means that this is safe in
practice, yet it is still undefined behaviour). Fix this by only
initializing the table from one place that is guarded by a single AVOnce.
This also avoids unnecessary duplications of the init code.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
The whole point of VLCs with their tables is to read more than one bit
at a time; therefore max_depth, the number of times one has to
(maximally) read further bits is given by ceil(max_code_length / table_bits)
which in the case of ATRAC9's coefficient VLCs gives an upper bound of
two. Instead the maximum length of a code of the given VLC has been used
(which is not even a compile-time constant). Use two instead.
Furthermore, given that this was the only usage of the field containing
the maximum of all the code lengths of a given VLC the field has been
removed from its containing struct.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
