and remove FF_CODEC_CAP_INIT_THREADSAFE
All our native codecs are already init-threadsafe
(only wrappers for external libraries and hwaccels
are typically not marked as init-threadsafe yet),
so it is only natural for this to also be the default state.
Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
In C, qualifiers for arrays are broken:
const VLC_TYPE (*foo)[2] is a pointer to an array of two const VLC_TYPE
elements and unfortunately this is not compatible with a pointer
to a const array of two VLC_TYPE, because the latter does not exist
as array types are never qualified (the qualifier applies to the base
type instead). This is the reason why get_vlc2() doesn't accept
a const VLC table despite not modifying the table at all, as
there is no automatic conversion from VLC_TYPE (*)[2] to
const VLC_TYPE (*)[2].
Fix this by using a structure VLCElem for the VLC table.
This also has the advantage of making it clear which
element is which.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This is possible, because every given FFCodec has to implement
exactly one of these. Doing so decreases sizeof(FFCodec) and
therefore decreases the size of the binary.
Notice that in case of position-independent code the decrease
is in .data.rel.ro, so that this translates to decreased
memory consumption.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Up until now, codec.h contains both public and private parts
of AVCodec. This exposes the internals of AVCodec to users
and leads them into the temptation of actually using them
and forces us to forward-declare structures and types that
users can't use at all.
This commit changes this by adding a new structure FFCodec to
codec_internal.h that extends AVCodec, i.e. contains the public
AVCodec as first member; the private fields of AVCodec are moved
to this structure, leaving codec.h clean.
Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Also move FF_CODEC_TAGS_END as well as struct AVCodecDefault.
This reduces the amount of files that have to include internal.h
(which comes with quite a lot of indirect inclusions), as e.g.
most encoders don't need it. It is furthemore in preparation
for moving the private part of AVCodec out of the public codec.h.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This avoids unnecessary rebuilds of most source files if only the
list of enabled components has changed, but not the other properties
of the build, set in config.h.
Signed-off-by: Martin Storsjö <martin@martin.st>
This automatically makes the FLV, H.263, H.263+, Intel H.263,
MPEG-4, RealVideo 1.0 and RealVideo 2.0 decoders init-threadsafe.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This is in preparation for further commits that will stop
using ThreadFrame for frame-threaded codecs that don't use
ff_thread_(await|report)_progress(); the API for those codecs
having inter-frame depdendencies will live in threadframe.h.
Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
use_intra_dc_vlc is currently kept in sync between frame threads
in mpeg4_update_thread_context(), yet it is set when decoding
blocks, i.e. after ff_thread_finish_setup(). This is a data race
and therefore undefined behaviour.
This race can be fixed easily by moving the variable from the context
to the stack: use_intra_dc_vlc is only read in
mpeg4_decode_block() and only if one is decoding an intra block.
There are three callsites for this function: One in
mpeg4_decode_partitioned_mb() which always sets use_intra_dc_vlc
before the call and two in mpeg4_decode_mb(). One of these callsites
is for intra blocks and use_intra_dc_vlc is set before it;
the last callsite is for non-intra blocks, where use_intra_dc_vlc
is ignored. So if it is used, it always uses a new value and can
therefore be moved to the stack.
The above also explains why this data race did not lead to
FATE-test failures.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This is possible now that dealing with the Simple Studio Profile
has been moved to mpeg4videodec.c. It also allows to avoid
allocations, because one can simply put the required buffers
on the context (if one made these buffers part of MpegEncContext,
the memory would be wasted for every codec other than MPEG-4).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
These messages belong together, yet they can be torn apart
if some other call to av_log() happens between them.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Both the MPEG-4 parser as well as the decoder initialized
several VLCs. There is a "static int done = 0;" in order to
guard against initializing these multiple times, but this does
not work when several threads try to initialize these VLCs
concurrently, which can happen when initializing several parsers
at the same time (they don't use the global lock that is used
for codecs without the FF_CODEC_CAP_INIT_THREADSAFE cap; actually,
they don't use any lock at all).
Since ff_mpeg4_decode_picture_header() now aborts early when called
from the parser, it no longer needs to have these VLCs initialized
at all. This commit therefore does exactly this.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Namely, skip some elements that are only useful for a decoder
when calling ff_mpeg4_decode_picture_header() from the MPEG-4 parser.
In particular, this ensures that the VLCs need no longer be
initialized by the parser.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
It is supported only by a few decoders (h263, h263p, mpeg(1|2|)video
and mpeg4) and is entirely redundant with parsers. Furthermore, using
it leads to missing frames, as flushing the decoder at the end does not
work properly.
Co-authored-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Given that the AVCodec.next pointer has now been removed, most of the
AVCodecs are not modified at all any more and can therefore be made
const (as this patch does); the only exceptions are the very few codecs
for external libraries that have a init_static_data callback.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
Up until now the RLTable ff_mpeg4_rl_intra was initialized by both mpeg4
decoder and encoder (except the VLCs that are only used by the decoder).
This is an obstacle to making these codecs init-threadsafe, so move
initializing this to a single function that is guarded by a dedicated
AVOnce.
Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This mostly reverts commit 4b2863ff01.
Said commit removed the freeing code from ff_mpv_common_init(),
ff_mpv_common_frame_size_change() and ff_mpeg_framesize_alloc() and
instead added the FF_CODEC_CAP_INIT_CLEANUP to several codecs that use
ff_mpv_common_init(). This introduced several bugs:
a) Several decoders using ff_mpv_common_init() in their init function were
forgotten: This affected FLV, Intel H.263, RealVideo 3.0 and V4.0 as well as
VC-1/WMV3.
b) ff_mpv_common_init() is not only called from the init function of
codecs, it is also called from AVCodec.decode functions. If an error
happens after an allocation has succeeded, it can lead to memleaks;
furthermore, it is now possible for the MpegEncContext to be marked as
initialized even when ff_mpv_common_init() returns an error and this can
lead to segfaults because decoders that call ff_mpv_common_init() when
decoding a frame can mistakenly think that the MpegEncContext has been
properly initialized. This can e.g. happen with H.261 or MPEG-4.
c) Removing code for freeing from ff_mpeg_framesize_alloc() (which can't
be called from any init function) can lead to segfaults because the
check for whether it needs to allocate consists of checking whether the
first of the buffers allocated there has been allocated. This part has
already been fixed in 76cea1d2ce.
d) ff_mpv_common_frame_size_change() can also not be reached from any
AVCodec.init function; yet the changes can e.g. lead to segfaults with
decoders using ff_h263_decode_frame() upon allocation failure, because
the MpegEncContext will upon return be flagged as both initialized and
not in need of reinitialization (granted, the fact that
ff_h263_decode_frame() clears context_reinit before the context has been
reinited is a bug in itself). With the earlier version, the context
would be cleaned upon failure and it would be attempted to initialize
the context again in the next call to ff_h263_decode_frame().
While a) could be fixed by adding the missing FF_CODEC_CAP_INIT_CLEANUP,
keeping the current approach would entail adding cleanup code to several
other places because of b). Therefore ff_mpv_common_init() is again made
to clean up after itself; the changes to the wmv2 decoder and the SVQ1
encoder have not been reverted: The former fixed a memleak, the latter
allowed to remove cleanup code.
Fixes: double free
Fixes: ff_free_picture_tables.mp4
Fixes: ff_mpeg_update_thread_context.mp4
Fixes: decode_colskip.mp4
Fixes: memset.mp4
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This reverts commit 6ac0e78183.
The mpeg4video parser can reach code that presumes that a certain VLC
has been initialized; yet Libav did not ensure this and Libav bug #1012
[1] is about an ensuing crash.
Instead of fixing the root cause a simple check for whether said VLC
has already been initialized was added; said check is inherently racy.
The proper fix is of course to ensure that the VLC is initialized and
commit 7c76eaeca2 already ensured this,
so there was no need to merge 6ac0e78183
at all. This commit therefore reverts said commit.
[1]: https://bugzilla.libav.org/show_bug.cgi?id=1012
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Also fix the indentation of decode_studio_vol_header while at it;
it was wrong since 177133a0f4.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
The RLTables whose VLC tables are only used for intra blocks only use
the very first VLC table; yet all 32 have been initialized. This commit
stops this by switching to INIT_FIRST_VLC_RL. This saves 201624B from
the .bss segment; in case the decoder is actually used, this translates
into less memory used.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Switching from ff_init_vlc_sparse() to ff_init_vlc_from_lengths()
allows to replace codes which are so long that they need to be stored
in an uint16_t by symbols which fit into an uint8_t; and even these can
be avoided in case of the sprite trajectory VLC.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
The longest code here is 12 bits long and can be read in two attempts.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Fixes: signed integer overflow: -144876608 * 16 cannot be represented in type 'int'
Fixes: 22782/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG4_fuzzer-6039584977977344
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes: out of array access
Fixes: 23327/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG4_fuzzer-5134822992510976
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The current design, where
- proper init is called for the first per-thread context
- first thread's private data is copied into private data for all the
other threads
- a "fixup" function is called for all the other threads to e.g.
allocate dynamically allocated data
is very fragile and hard to follow, so it is abandoned. Instead, the
same init function is used to init each per-thread context. Where
necessary, AVCodecInternal.is_copy can be used to differentiate between
the first thread and the other ones (e.g. for decoding the extradata
just once).
Andreas Rheinhardt
Martin Storsjö
Anton Khirnov
Andreas Rheinhardt
James Almer
Paul B Mahol
Carl Eugen Hoyos
Michael Niedermayer
Limin Wang
Mark Thompson