[MPlayer-users] Playing QHD (3840x2160) material with mplayer

[Dean S. Messing]

On 11 Apr 2008, Reimar Doeffinger wrote:
> On Apr 11, 2008  Dominik 'Rathann' Mierzejewski wrote:
> > On Friday, 11 April 2008 at 00:01, Dean S. Messing wrote:
> > > I am trying to play uncompressed rgb QHD material with mplayer.  After
> > > modifying transcode to handle QHD, I was able to generate an .avi from
> > > the .png frames of the video.  I can play them with mplayer using 
> > > "-vo x11" but only at about 14fps.  I need to play at 24fps.
> > > 
> > > When I use the xv output driver, I get the Transcript below.  Is it
> > > straightforward to increase the accepted dimensions of the xv output
> > > driver in the mplayer source code?
> > 
> > It's not a limitation of MPlayer. It's a limitation of the driver for your
> > graphics card or even a limitation of the card itself (video overlay size).
> > 
> > You could try using -vo gl:yuv=X with various X values or -vo xvidix (see
> > man mplayer), but there are other limiting factors as well.
> 
> At this resolution, I think at best some really new cards will be able
> to handle it via -vo gl, probably only -vo gl2 will work. And it
> certainly should not be that much faster that x11.
> 
> > talking 4.7Gbps (570MB/s) of data here. A decent PCIe 2.0 card can handle
> > that (even with one lane), but the limiting factor is the storage. So
> > unless you're playing from a RAM disk or a 10Gb network (even an SSD drive
> > is too slow), you won't be able to play it in real time. And I'm not
> > counting the decoding time here.
> 
> AFAICT the source is uncompressed, which is likely much, much slower
> than some simple compression, esp. if it is a multicore CPU and a codec
> with good multithreading support. MPEG-2 can also be decoded on the
> graphics card with xvmc, which decreases the bandwidth, though I have
> some doubts it will work well at that resolution.
> 

Thanks, Reimar, for your reply.

I will immediately try your suggestions and report back.  You are
correct: the source is uncompressed RGB 24-bit video.  See the reply I
just sent to Dominik in this thread for my system description.  When I
initially specified the system I was assured that it would have the
heft to play at 60fps _from memory_ which is all I require.  This was
"in principle".  At the time, the software went unspecified.  I
assumed that mplayer, being the King of players, could be made to do
it if anything could.

Your remark about compressing the source partially answers a question
I had in my other message.  Note that I cannot introduce artifacts so
the bit-rate needs to be high, say 2Gbps, which should be close to
lossless.  But I have little experience with the software tools
(mencoder / transcode /ffmpeg ?) for compressing video.  And, like
you, I wonder if these can deal with QHD.

Thanks for your help.

Dean