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This mostly reverts commit4b2863ff01. 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 in76cea1d2ce. 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>
FFmpeg README
FFmpeg is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.
Libraries
libavcodecprovides implementation of a wider range of codecs.libavformatimplements streaming protocols, container formats and basic I/O access.libavutilincludes hashers, decompressors and miscellaneous utility functions.libavfilterprovides a mean to alter decoded Audio and Video through chain of filters.libavdeviceprovides an abstraction to access capture and playback devices.libswresampleimplements audio mixing and resampling routines.libswscaleimplements color conversion and scaling routines.
Tools
- ffmpeg is a command line toolbox to manipulate, convert and stream multimedia content.
- ffplay is a minimalistic multimedia player.
- ffprobe is a simple analysis tool to inspect multimedia content.
- Additional small tools such as
aviocat,ismindexandqt-faststart.
Documentation
The offline documentation is available in the doc/ directory.
The online documentation is available in the main website and in the wiki.
Examples
Coding examples are available in the doc/examples directory.
License
FFmpeg codebase is mainly LGPL-licensed with optional components licensed under GPL. Please refer to the LICENSE file for detailed information.
Contributing
Patches should be submitted to the ffmpeg-devel mailing list using
git format-patch or git send-email. Github pull requests should be
avoided because they are not part of our review process and will be ignored.