wm4
77a00e444f
This fixes playback of the sample linked by FFmpeg ticket 2508. The fix follows ffmpeg commit 6158a3b (although it's not exactly the same). The problem here is that the file contains an apparently non-sense DefaultDuration value. DefaultDuration for audio tracks is used to derive PTS values for packets with no timestamps, like they can happen with frames inside a laced block. So the first packet of a SimpleBlock will have a correct PTS, while the PTS values of the following packets are calculated using DefaultDuration, and thus are broken. This leads to seemingly ok playback, but broken A/V sync. Not using the DefaultDuration value will leave the PTS values of these packets unset, and the audio decoder can derive them from the output instead. The fix more or less uses a heuristic to detect the broken case: if the sample rate is 8 KHz (Matroska default, can assume unset), and the codec is AC3 (as the broken file did), don't use it. I'm not sure why this should be done only for AC3, maybe the muxing application (mkvmerge v4.9.1) has known issues with AC3. AC3 also doesn't support 8 KHz as sample rate natively. (By the way, I'm not sure why we should honor the DefaultDuration at all for audio. It doesn't seem to be needed. You can't seek to these frames, and decoders should always be able to produce perfect PTS values by adding the duration of the decoded audio to the first PTS.)
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. For
more information see the output of ./configure --help for a list of options,
or look at the list of enabled and disabled features printed after running
./configure. If you think you have support for some feature installed
but configure fails to detect it, the file config.log may contain
information about the reasons for the failure.
Essential dependencies (incomplete list):
- gcc or clang
- X development headers (xlib, X extensions, libvdpau, libGL, libXv, ...)
- Audio output development headers (libasound, pulseaudio)
- fribidi, freetype, fontconfig development headers (for libass)
- libass
- FFmpeg libraries (libavutil libavcodec libavformat libswscale libpostproc)
- libjpeg
- libquvi if you want to play Youtube videos directly
- libx264/libmp3lame/libfdk-aac if you want to use encoding (has to be explicitly enabled when compiling ffmpeg)
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.
configure --enable-* parameters
The --enable-* parameters unconditionally force options on, completely skipping autodetection. This behavior is unlike what you may be used to from autoconf-based configure scripts that can decide to override you. This greater level of control comes at a price. You may have to provide the correct compiler and linker flags yourself. If you used one of these options and experience a compilation or linking failure, make sure you have passed the necessary compiler/linker flags to configure.
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
You can find us on IRC in #mpv-player on irc.freenode.net