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f82748d5e0
Consider the following sequence of NALUs (with some PPSs etc. omitted for brevity): 1. SPS (ID=0, content=A) 2. IDR (SPS=0) 3. IDR (SPS=0) 4. SPS (ID=0, content=B) 5. TRAIL (SPS=0) When decode_sps is called for NALU 3., ps->sps_id_used is cleared as IDRs are one way of forming a CLVSS. Then, old_sps is non-NULL containing the result of calling decode_sps for NALU 2. We haven't received any SPSs between NALUs 2. and 3., therefore old_sps and rsps are identical and the function returns. The issue is that, at this point, ps->sps_id_used is still zero despite the SPS being used for IDR 3. This results in the check for conflicting SPSs not working properly when decode_sps is called for NALU 5., allowing prediction between pictures with different SPSs and probably all sorts of other shenanigans. Patch addresses the problem outlined above by also setting ps->sps_id_used in the early return case.
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 means to alter decoded audio and video through a directed graph of connected 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.