fe251f77c8
The documentation of av_write_frame() explicitly states that the function doesn't take ownership of the packets sent to it; while av_write_frame() does not directly unreference the packets after having written them, it nevertheless modifies the packet in various ways: 1. The timestamps might be modified either by prepare_input_packet() or compute_muxer_pkt_fields(). 2. If a bitstream filter gets applied, it takes ownership of the reference and the side-data in the packet sent to it. In case of do_packet_auto_bsf(), the end result is that the returned packet contains the output of the last bsf in the chain. If an error happens, a blank packet will be returned; a packet may also simply not lead to any output (vp9_superframe). This also implies that side data needs to be really copied and can't be shared with the input packet. The method choosen here minimizes copying of data: When the input isn't refcounted and no bitstream filter is applied, the packet's data will not be copied. Notice that packets that contain uncoded frames are exempt from this because these packets are not owned by and returned to the user. This also moves unreferencing the packets containing uncoded frames to av_write_frame() in the noninterleaved codepath; in the interleaved codepath, these packets are already freed in av_interleaved_write_frame(), so that unreferencing the packets in write_uncoded_frame_internal() is no longer needed. It has been removed. Reviewed-by: Marton Balint <cus@passwd.hu> 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.