No description
Currently skip_samples is set to start_pad if sample_time is lesser or equal to 0. This can cause issues if the stream starts with packets that have negative pts. Calling avformat_seek_file() with ts set to 0 on such streams makes the mov demuxer return the right corresponding packets (near the 0 timestamp) but set skip_samples to start_pad which is incorrect as the audio decoder will discard the returned samples according to skip_samples from the first packet it receives (which has its timestamp near 0). For example, considering the following audio stream with start_pad=1344: [PKT pts=-1344] [PKT pts=-320] [PKT pts=704] [PKT pts=1728] [...] Calling avformat_seek_file() with ts=0 makes the next call to av_read_frame() return the packet with pts=-320 and a skip samples side data set to 1344 (start_pad). This makes the audio decoder incorrectly discard (1344 - 320) samples. This commit makes the move demuxer adjust skip_samples according to the stream start_pad, seek timestamp and first sample timestamp. The above example will now result in av_read_frame() still returning the packet with pts=-320 but with a skip samples side data set to 320 (src_pad - (seek_timestamp - first_timestamp)). This makes the audio decoder only discard 320 samples (from pts=-320 to pts=0). Signed-off-by: Marton Balint <cus@passwd.hu> |
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| compat | ||
| doc | ||
| ffbuild | ||
| fftools | ||
| libavcodec | ||
| libavdevice | ||
| libavfilter | ||
| libavformat | ||
| libavresample | ||
| libavutil | ||
| libpostproc | ||
| libswresample | ||
| libswscale | ||
| presets | ||
| tests | ||
| tools | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .travis.yml | ||
| Changelog | ||
| configure | ||
| CONTRIBUTING.md | ||
| COPYING.GPLv2 | ||
| COPYING.GPLv3 | ||
| COPYING.LGPLv2.1 | ||
| COPYING.LGPLv3 | ||
| CREDITS | ||
| INSTALL.md | ||
| LICENSE.md | ||
| MAINTAINERS | ||
| Makefile | ||
| README.md | ||
| RELEASE | ||
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.