ab201ce042
A mkv sample file was provided to me, which contained a moving PGS subtitle track, with the same track rendered into the video as reference. The subtitle track appeared to stutter (while the video one was smooth). It turns out this was a timestamp rounding issue in mpv. The subtitle timestamps in the file match the video ones exactly. They're the same within the mpv demuxer too. Unfortunately, the conversion from and to libavcodec timestamps is lossy, because mpv uses a non-integer timebase, while libavcodec supports integers only. See mp_pts_to_av() and mp_pts_from_av(). The recovered timestamp is almost the same, but is off by a very minor part. As a result, the timestamps won't compare equal, and if that happens, display of the subtitle frame is skipped. Subtitle timestamps don't go through this conversion because... libavcodec is special? The libavcodec subtitle API is special. Fix this by giving it a microsecond of slack. This is basically as if we used an internal microseconds integer timebase, but only for the purpose of image subtitle display. The same could happen to sd_ass, except in practice it doesn't. ASS subtitles (well, .ass files) inherently use a timebase incompatible to video, so to ensure frame exactness, ASS timestamps are usually set to slightly before the video frame's. Discussion of better solutions: One could rewrite mpv not to use float timestamps. You'd probably pick some integer timebase instead (like microseconds), which would avoid the libavcodec interop issue. At the very least this would be a lot of work. It would be interesting to know whether the rounding in ther mpv<->lavc timestamp conversion could be fixed to round-trip in this case. The conversion tries to avoid problems by using the source timebase (e.g. milliseconds with mkv). But in general some rounding is unavoidable, because something between decoder and lowest demuxer layer could transform the timestamps. One could extend libavcodec to attach arbitrary information to avpacket and return it in the resulting avframe. To some degree, such a mechanism already exists (side data). But there are certain problems that make this unfeasible and broken. One could pass through exact mpv float timestamps by reinterpret-casting them to int64_t, the FFmpeg timestamp type. Actually mpv used to do this. But there were problems, such as FFmpeg (or things used by FFmpeg) wanting to interpret the timestamps. Awful shit that make mpv change to the current approach. There's probably more but I'm getting bored. With some luck I wasted precious seconds of your life with my nonsense. |
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|---|---|---|
| .github | ||
| audio | ||
| ci | ||
| common | ||
| demux | ||
| DOCS | ||
| etc | ||
| filters | ||
| input | ||
| libmpv | ||
| misc | ||
| options | ||
| osdep | ||
| player | ||
| stream | ||
| sub | ||
| ta | ||
| test | ||
| TOOLS | ||
| video | ||
| waftools | ||
| .gitignore | ||
| .travis.yml | ||
| appveyor.yml | ||
| bootstrap.py | ||
| Copyright | ||
| LICENSE.GPL | ||
| LICENSE.LGPL | ||
| mpv_talloc.h | ||
| README.md | ||
| RELEASE_NOTES | ||
| VERSION | ||
| version.sh | ||
| wscript | ||
| wscript_build.py | ||
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. Below is a list of some important requirements.
The mpv build system uses waf, but we don't store it in the
repository. The ./bootstrap.py script will download the latest version
of waf that was tested with the build system.
For a list of the available build options use ./waf configure --help. If
you think you have support for some feature installed but configure fails to
detect it, the file build/config.log may contain information about the
reasons for the failure.
NOTE: To avoid cluttering the output with unreadable spam, --help only shows
one of the two switches for each option. If the option is autodetected by
default, the --disable-*** switch is printed; if the option is disabled by
default, the --enable-*** switch is printed. Either way, you can use
--enable-*** or --disable-** regardless of what is printed by --help.
To build the software you can use ./waf build: the result of the compilation
will be located in build/mpv. You can use ./waf install to install mpv
to the prefix after it is compiled.
Example:
./bootstrap.py
./waf configure
./waf
./waf install
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 (optional, 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 --enable-lgpl.
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.freenode.net - Developer IRC Channel:
#mpv-develonirc.freenode.net