Kacper Michajłow
68b1d10da5
The old code had several interacting problems that prevented A/V from reaching a steady state. When the A/V difference was large, it applied the maximum allowed compensation in one step. That was fine for catching up, but the value was never re-evaluated, so audio speed routinely overshot the target. Once the difference crossed zero (or re-entered the acceptable range) it would run a linear regression over recent av_diff samples and snap the audio speed to the estimated drift. The fatal flaw was that those samples already included the controller's own compensation: even when the underlying drift was zero, the controller would "detect" the drift it had just induced and try to cancel it. Between these rare, sparse updates audio speed stayed frozen, so in practice the controller was introducing drift more than it was fixing it. On high fps outputs, where the vsync range is tight, this degenerated into a ping-pong: overshoot, snap back, overshoot again, never settling. The new code replaces the bang-bang direction controller and one-shot regression with a proportional controller driven by a low-pass-filtered av_diff. The LP filter (1 s time constant) rejects per-frame vsync jitter so the compensation no longer chases noise. The target then decays av_diff exponentially toward zero with a 10 s recovery time. Adaptive slew caps per-frame motion to the desired correction magnitude, so large excursions are absorbed quickly while near-equilibrium motion stays below audibility. The result is a continuous, gentle control loop that actually reaches steady state and does so without audible audio-speed modulation.
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 (usually, only the latest releases of distributions are actively supported), Windows 10 1607 or later, or macOS 10.15 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. On such GPUs, it's recommended to use
--profile=fastfor smooth playback. 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.
mpv does not go out of its way to break on older hardware or old, unsupported operating systems, but development is not done with them in mind. Keeping compatibility with such setups is not guaranteed. If things work, consider it a happy accident.
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.
Changes to the default OSC bindings are indicated in restore-osc-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
For libplacebo, meson can use a git check out as a subproject for a convenient way to compile mpv if a sufficient libplacebo version is not easily available in the build environment. It will be statically linked with mpv. Example:
mkdir -p subprojects
git clone https://code.videolan.org/videolan/libplacebo.git --depth=1 --recursive subprojects/libplacebo
Essential dependencies (incomplete list):
- gcc or clang
- X development headers (xlib, xrandr, xext, xscrnsaver, xpresent, libvdpau, libGL, GLX, EGL, xv, ...)
- Audio output development headers (libasound/ALSA, pulseaudio)
- FFmpeg libraries (libavutil libavcodec libavformat libswscale libavfilter and either libswresample or libavresample)
- libplacebo
- 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, nasm 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 macOS, and Arabic/Indic scripts on any platform)
FFmpeg dependencies (when building FFmpeg):
- gcc or clang, nasm 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, see Windows compilation.
Release cycle
Once or twice a year, a release is cut off from the current development state and is assigned a 0.X.0 version number. No further maintenance is done, except in the event of security issues.
The goal of releases is to make Linux distributions happy. Linux distributions are also expected to apply their own patches in case of bugs.
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.
Questions can be asked in the discussions or on IRC (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)
- Discussions: discussions
- User IRC Channel:
#mpvonirc.libera.chat - Developer IRC Channel:
#mpv-develonirc.libera.chat