[MPlayer-users] vaapi decode H.264 with MPEG-2 decoder?

[Zhang Weiwu]

Hello. I am just starting to try vaapi on my Radeon HD 6290. A test run shows -vo vaapi did reduce CPU consumption, but the output is mysterious to me.

$ mplayer *.mkv
MPlayer UNKNOWN-4.7 (C) 2000-2012 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing [巴黎圣母院].Notre.Dame.de.Paris.1999.DVDrip.x264.DTS.by.writeclay.CD2.mkv.

[...snip... the full output is at the end of this email...]

[VD_FFMPEG] Trying pixfmt=1.
Movie-Aspect is 1.50:1 - prescaling to correct movie aspect.
VO: [vaapi] 720x480 => 720x480 H.264 VA-API Acceleration
[VD_FFMPEG] XVMC-accelerated MPEG-2.
xvba_video: XVBA_DestroySurface(): status 20/  0 31% 116%  3.1% 9 0

It basically says, yes, video output is vaapi, and video decoder is
XVMC-accelerated MPEG-2. This is what confuses me. The video is
apparently H.264, which can be called MPEG-4, but never MPEG-2.

I took a wild guess that MPEG-4 is perhaps built on top of MPEG-2, thus
vaapi is off-loading part of decoding work to the hardware MPEG-2
decoder, and part of the work still has to be done on CPU. Further
perhaps MPEG-2 is the best my video card can do.

But half an hour research on Google didn't find me evidence supporting
this hypothesis, only that XVMC is obsoleted by VAAPI in the case of MythTV.

So what does this "XVMC-accelerated MPEG-2" mean?

--

$ mplayer *.mkv
MPlayer UNKNOWN-4.7 (C) 2000-2012 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing [巴黎圣母院].Notre.Dame.de.Paris.1999.DVDrip.x264.DTS.by.writeclay.CD2.mkv.
libavformat version 54.25.104 (internal)
libavformat file format detected.
[lavf] stream 0: video (h264), -vid 0
[lavf] stream 1: audio (dca), -aid 0
[lavf] stream 2: subtitle (dvdsub), -sid 0, -slang fre
[lavf] stream 3: subtitle (dvdsub), -sid 1, -slang chi
[lavf] stream 4: subtitle (dvdsub), -sid 2, -slang chi
VIDEO:  [H264]  720x480  0bpp  29.970 fps    0.0 kbps ( 0.0 kbyte/s)
Clip info:
  creation_time: 2009-09-01 23:57:40
Load subtitles in ./
libva: VA-API version 0.32.0
Xlib:  extension "XFree86-DRI" missing on display ":0.0".
libva: va_getDriverName() returns 0
libva: Trying to open /usr/lib/x86_64-linux-gnu/dri/fglrx_drv_video.so
libva: va_openDriver() returns 0
Opening video filter: [ass auto=1]
Couldn't open video filter 'ass'.
ASS: cannot add video filter
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
libavcodec version 54.54.100 (internal)
Selected video codec: [ffh264] vfm: ffmpeg (FFmpeg H.264)
==========================================================================
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 48000 Hz, 2 ch, s16le, 1536.0 kbit/100.00% (ratio: 192000->192000)
Selected audio codec: [ffdca] afm: ffmpeg (FFmpeg DTS)
==========================================================================
AO: [alsa] 48000Hz 2ch s16le (2 bytes per sample)
Starting playback...
Unsupported PixelFormat 61
[VD_FFMPEG] Trying pixfmt=1.
Movie-Aspect is 1.50:1 - prescaling to correct movie aspect.
VO: [vaapi] 720x480 => 720x480 H.264 VA-API Acceleration
[VD_FFMPEG] XVMC-accelerated MPEG-2.
xvba_video: XVBA_DestroySurface(): status 20/  0 31% 116%  3.1% 9 0