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Preparation so that various things related to video can run in different threads. One part to this is making the video surface pool safe. Another issue is the preemption mechanism, which continues to give us endless pain. In theory, it's probably impossible to handle preemption 100% correctly and race-condition free, unless _every_ API user in the same process uses a central, shared mutex to protect every vdpau API call. Otherwise, it could happen that one thread recovering from preemption allocates a vdpau object, and then another thread (which hasn't recovered yet) happens to free the object for some reason. This is because objects are referenced by integer IDs, and vdpau will reuse IDs invalidated by preemption after preemption. Since this is unreasonable, we're as lazy as possible when it comes to handling preemption. We don't do any locking around the mp_vdpau_ctx fields that are normally immutable, and only can change when recovering from preemption. In practice, this will work, because it doesn't matter whether not-yet-recovered components use the old or new vdpau function pointers or device ID. Code calls mp_vdpau_handle_preemption() anyway to check for the preemption event and possibly to recover, and that function acquires the lock protecting the preemption state. Another possible source of potential grandiose fuckup is the fact that the vdpau library is in fact only a tiny wrapper, and the real driver lives in a shared object dlopen()ed by the wrapper. The wrapper also calls dlclose() on the loaded shared object in some situations. One possible danger is that failing to recreate a vdpau device could trigger a dlclose() call, and that glibc might unload it. Currently, glibc implements full unloading of shared objects on the last dlclose() call, and if that happens, calls to function pointers pointing into the shared object would obviously crash. Fortunately, it seems the existing vdpau wrapper won't trigger this case and never unloads the driver once it's successfully loaded. To make it short, vdpau preemption opens up endless depths of WTFs. Another issue is that any participating thread might do the preemption recovery (whichever comes first). This is easier to implement. The implication is that we need threadsafe xlib. We just hope and pray that this will actually work. This also means that once vdpau code is actually involved in a multithreaded scenario, we have to add XInitThreads() to the X11 code.
mpv
Overview
mpv is a movie player based on MPlayer and mplayer2. It supports a wide variety of video file formats, audio and video codecs, and subtitle types.
If you are wondering what's different from mplayer2 and MPlayer you can read more about the changes.
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 your source tree. The script './bootstrap.py' 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.
NOTE: Using the old build system (with ./old-configure) should still work,
but will be removed in a future version of mpv.
Essential dependencies (incomplete list):
- gcc or clang
- X development headers (xlib, X extensions, libvdpau, libGL, libXv, ...)
- Audio output development headers (libasound, pulseaudio)
- FFmpeg libraries (libavutil libavcodec libavformat libswscale libavresample) At least FFmpeg 2.1.4 or Libav 10 is required.
- libjpeg (for screenshots)
- libquvi if you want to play Youtube videos directly
Libass dependencies:
- gcc or clang, yasm on x86 and x86_64
- fribidi, freetype, fontconfig development headers (for libass)
FFmpeg dependencies:
- gcc or clang, yasm on x86 and x86_64
- OpenSSL (has to be explicitly enabled when compiling ffmpeg)
- libx264/libmp3lame/libfdk-aac if you want to use encoding (has to be explicitly enabled when compiling ffmpeg)
- Libav also works, but some features will not work. (See section below.)
Most of the above libraries are available in suitable versions on normal Linux distributions. However FFmpeg is an exception (distro versions may be too old to work at all or work well). For that reason you may want to use the separately available build wrapper (mpv-build) that first compiles FFmpeg libraries and libass, and then compiles the player statically linked against those.
If you are running Mac OSX and using homebrew we provide homebrew-mpv, an up to date formula that compiles mpv with sensible dependencies and defaults for OSX.
FFmpeg vs. Libav
Generally, mpv should work with the latest release as well as the git version of both FFmpeg and Libav. But FFmpeg is preferred, and some mpv features work with FFmpeg only. See the wiki article about the issue.
Bug reports
Please use the issue tracker provided by GitHub to send us bug reports or feature requests.
Contributing
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.
Contacts
These forms of contact are meant to ask questions about mpv usage, give feedback on mpv and discuss it's development.
If possible, please avoid posting bugs here and use the issue tracker instead.
- Users IRC Channel:
#mpv-playeronirc.freenode.net - Users Mailing List:
mpv-users@googlegroups.com(Archive / Subscribe). - Devel Mailing List:
mpv-devel@googlegroups.com(Archive / Subscribe)
To contact the mpv team in private write to mpv-team@googlegroups.com.