Philip Langdale
7d7ef05f10
I'm currently not convinced that the way the output_chain is handled as part of reconfiguration is correct. If there is an event requiring reconfiguration, such as toggling the use of hwdec, we currently do not ensure that the filter chain is fully drained first. This creates a situation where the filter chain is invalidated while the autoconvert's sub filter (that does the real work) still has a frame to process and pass on. As the autoconvert code calls mp_subfilter_drain_destroy(), it returns early to allow for draining before destroying the subfilter, but that means the subfilter is still present in its original configuration, and no actually draining is done before the existing filters reinitialise themselves. This leads to a situation where, if a hardware scaling filter is being used by autoconvert, that filter is still present and responds when told to reinitialise. But it cannot successfully reinitialise if the triggering event is disabling hw decoding, as the input frame to the filter will now be a software frame, so reinit fails, leading to total failure of the filter chain, which is a fatal error, and we exit. I think this was never noticed before, because I think it's not possible for the hwtransfer filter to be active in a situation where you can dynamically change the state such that the input or output formats of the output chain are invalidated. eg: If the autoconverter is activated because of `--vf=format=vaapi`, it is actually not possible to toggle hwdec off, as the explicit user filter ensure the hwdec is always present and active. So, my solution here is to destroy the sub filter, regardless of whether it needs draining or not. We simply have no opportunity to drain and reconfigure in the correct order, and we must consider the remaining frame in the filter as a casualty of the toggling process. I'm sure there is a more substantial rework of the output_chain reconfiguration process that could ensure draining before reconfiguration begins, but my ambitions do not currently extend that far.
mpv
- External links
- Overview
- System requirements
- Downloads
- Changelog
- Compilation
- Release cycle
- Bug reports
- Contributing
- License
- Contact
External links
Overview
mpv is a free (as in freedom) media player for the command line. It supports a wide variety of media file formats, audio and video codecs, and subtitle types.
There is a FAQ.
Releases can be found on the release list.
System requirements
- A not too ancient Linux, Windows 7 or later, or OSX 10.8 or later.
- A somewhat capable CPU. Hardware decoding might help if the CPU is too slow to
decode video in realtime, but must be explicitly enabled with the
--hwdecoption. - A not too crappy GPU. mpv's focus is not on power-efficient playback on
embedded or integrated GPUs (for example, hardware decoding is not even
enabled by default). Low power GPUs may cause issues like tearing, stutter,
etc. The main video output uses shaders for video rendering and scaling,
rather than GPU fixed function hardware. On Windows, you might want to make
sure the graphics drivers are current. In some cases, ancient fallback video
output methods can help (such as
--vo=xvon Linux), but this use is not recommended or supported.
Downloads
For semi-official builds and third-party packages please see mpv.io/installation.
Changelog
There is no complete changelog; however, changes to the player core interface are listed in the interface changelog.
Changes to the C API are documented in the client API changelog.
The release list has a summary of most of the important changes on every release.
Changes to the default key bindings are indicated in restore-old-bindings.conf.
Compilation
Compiling with full features requires development files for several external libraries. Mpv requires meson to build. Meson can be obtained from your distro or PyPI.
After creating your build directory (e.g. meson setup build), you can view a list
of all the build options via meson configure build. You could also just simply
look at the meson_options.txt file. Logs are stored in meson-logs within
your build directory.
Example:
meson setup build
meson compile -C build
meson install -C build
Essential dependencies (incomplete list):
- gcc or clang
- X development headers (xlib, xrandr, xext, xscrnsaver, xinerama, libvdpau, libGL, GLX, EGL, xv, ...)
- Audio output development headers (libasound/ALSA, pulseaudio)
- FFmpeg libraries (libavutil libavcodec libavformat libswscale libavfilter and either libswresample or libavresample)
- zlib
- iconv (normally provided by the system libc)
- libass (OSD, OSC, text subtitles)
- Lua (optional, required for the OSC pseudo-GUI and youtube-dl integration)
- libjpeg (optional, used for screenshots only)
- uchardet (optional, for subtitle charset detection)
- nvdec and vaapi libraries for hardware decoding on Linux (optional)
Libass dependencies (when building libass):
- gcc or clang, yasm on x86 and x86_64
- fribidi, freetype, fontconfig development headers (for libass)
- harfbuzz (required for correct rendering of combining characters, particularly for correct rendering of non-English text on OSX, and Arabic/Indic scripts on any platform)
FFmpeg dependencies (when building FFmpeg):
- gcc or clang, yasm on x86 and x86_64
- OpenSSL or GnuTLS (have to be explicitly enabled when compiling FFmpeg)
- libx264/libmp3lame/libfdk-aac if you want to use encoding (have to be explicitly enabled when compiling FFmpeg)
- For native DASH playback, FFmpeg needs to be built with --enable-libxml2 (although there are security implications, and DASH support has lots of bugs).
- AV1 decoding support requires dav1d.
- For good nvidia support on Linux, make sure nv-codec-headers is installed and can be found by configure.
Most of the above libraries are available in suitable versions on normal Linux distributions. For ease of compiling the latest git master of everything, you may wish to use the separately available build wrapper (mpv-build) which first compiles FFmpeg libraries and libass, and then compiles the player statically linked against those.
If you want to build a Windows binary, you either have to use MSYS2 and MinGW, or cross-compile from Linux with MinGW. See Windows compilation.
Release cycle
Every other month, an arbitrary git snapshot is made, and is assigned a 0.X.0 version number. No further maintenance is done.
The goal of releases is to make Linux distributions happy. Linux distributions are also expected to apply their own patches in case of bugs and security issues.
Releases other than the latest release are unsupported and unmaintained.
See the release policy document for more information.
Bug reports
Please use the issue tracker provided by GitHub to send us bug reports or feature requests. Follow the template's instructions or the issue will likely be ignored or closed as invalid.
Using the bug tracker as place for simple questions is fine but IRC is recommended (see Contact below).
Contributing
Please read contribute.md.
For small changes you can just send us pull requests through GitHub. For bigger changes come and talk to us on IRC before you start working on them. It will make code review easier for both parties later on.
You can check the wiki or the issue tracker for ideas on what you could contribute with.
License
GPLv2 "or later" by default, LGPLv2.1 "or later" with -Dgpl=false.
See details.
History
This software is based on the MPlayer project. Before mpv existed as a project, the code base was briefly developed under the mplayer2 project. For details, see the FAQ.
Contact
Most activity happens on the IRC channel and the github issue tracker.
- GitHub issue tracker: issue tracker (report bugs here)
- User IRC Channel:
#mpvonirc.libera.chat - Developer IRC Channel:
#mpv-develonirc.libera.chat