2008-06-02 15:32:03     BF537 playing video using mplayer

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2008-06-02 15:32:03     BF537 playing video using mplayer

Christopher Reder (UNITED STATES)

Message: 56584   


I am running a BF537 stamp kit with 64 MB of memory.  I am running it at 500/100Mhz and can run mplayer to play audio files and video files.  However, I am running into issues.  I know some similar topics have been covered recently but didn't want to hijack another thread.


I have a couple of quesitons I am hoping someone can answer:


1.  In order to get a video to play on a BF537, I have to have it as a really small resolution (320x240), not scaled, mp4, shown through the 7393.  However, a workmate has some Blackfin drivers that are outputting 640x480 video with audio without any issues but without uClinux.  I am trying to setup uClinux as close to that as possible and find it hard to believe that with 400x300 or so video, that I can't play it without it choking down where he can play full D1 just fine .  Is it merely a matter of the codecs?  (I did make the changes for multimedia optimizations I saw online with MULH but that mostly helped aac).


2.  With mplayer and the AD1836a kit, I can play a mp3 but it goes out every 2 seconds or so.  mp3play does not.  I am playing from a usb stick and it is using, according to mplayer, around 11-12 %.  This is both with code from SVN and that from the 2008 RC1.  Has anyone else seen this?




Is there a setup / config file out there which will build mplayer in such a way to optimize video and audio on the blackfin (along with the kernel for cache settings as I have done the write back cache mode suggested by erick). ?


Thanks in advance,






2008-06-02 18:48:19     Re: BF537 playing video using mplayer


Message: 56591   




The AD7393 needs graphics data in RGB colour space. Other video parts need video in YUV space.


When you decode video, you end up with YUV - Some video codecs just take this - others (like the 7393) need colur space conversion. So that is what the other one is doing - it really depends on what your final display will be LCD (RGB) or TV (YUV).


Also note that graphics are always in RGB space, not YUV.






2008-06-02 23:08:07     Re: BF537 playing video using mplayer

Christopher Reder (UNITED STATES)

Message: 56595   


Robin - Ok, that makes some sense of the performance hit.  basically it uses ITU656 instead of converting over...would that explain a file that would decode where mplayer is showing over 200%?  Perhaps it would.




So, to test this out to see if the processor can handle it, is it merely a matter of disabling the 7393?  What should I enable to get the 656 interface through the ppi active to make it equal?  I know my co worker is using a bf533 ez kit and pumping the video out the composite interface but like you said, it may be with an encoder that can take in the 656 format.










2008-06-04 17:42:12     Re: BF537 playing video using mplayer

Erick Hemphill (UNITED STATES)

Message: 56704   






Using the -vf scale=480:272 -sws 0 flags with your mplayer call helps. I find that it can scale just about anything I send to it. Admittedly.. full resolution DVD (720x576?) transcoded to mpeg1 of the same resolution plays noticeably slower than real time.




The other thing that really stablized mplayer was to start using a jffs2 filesystem and I turned off klogd and syslogd (maybe not smart.. but it keeps my memory free). I have 0 problems with audio only files and like I said... not perfect video, but at least it never crashes on me now. It seems to take it a while to index the filesystem.... mplayer takes about 10 seconds to run the first time I run it after bootup.