2009-02-06 20:00:13     BF527 ffmpeg performance

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2009-02-06 20:00:13     BF527 ffmpeg performance

Adam Dershowitz (UNITED STATES)

Message: 69015   

 

I downloaded and built uClinux 1.RC3 and the associated ffmpeg for the BF527 EZKit.  It seems to be working fine, but, I am trying to decode a 640x480 H.264 file and I am only getting 6-7 fps.

 

I am pretty sure that the issue is decompression because, as a test, I just dumped the output to null:

 

ffmpeg -i video.264 -f yuv4mpegpipe  /dev/null

 

From the forums it looks like a couple of years back some people where doing work on the ffmpeg code and were getting higher frame rates, for compression.  Decompression is generally a bunch faster.  But it seems that the most recent ffmpeg with uClinux is over a year old.

 

So, I am curious if anyone has been able to get any higher frame rates?  Are there any configurations or changes to the code that might help out some?

 

Any thoughts or guidance would be appreciated.

 

Thanks,

 

--Adam

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2009-02-08 20:59:22     Re: BF527 ffmpeg performance

Robin Getz (UNITED STATES)

Message: 69051   

 

Adam:

 

The exact frame rate will depend on the specific bitrate of the stream you are sending. For a high biterate stream - that size - (640x480) - on a 527 EZkit (133MHz SDRAM), seems about right - it really depends on the SDRAM speed, and the cache settings.

 

-Robin

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2009-02-09 17:25:10     Re: BF527 ffmpeg performance

Adam Dershowitz (UNITED STATES)

Message: 69150   

 

Thanks for the info...even if it was not what I was hoping to hear.

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2009-02-11 18:39:17     Re: BF527 ffmpeg performance

Adam Dershowitz (UNITED STATES)

Message: 69296   

 

For other reasons (trying to get ppi to work) I just switched from 20081.5RC3 to the nightly trunk build.  I got ffmpeg to build, but now I am seeing 3 fps when I was seeing 6-7 before.

 

I would guess this means that some default setting are different between the two versions.  Any suggestions for what might be cutting my performance in half like that?

 

Thanks,

 

--Adam

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2009-02-12 06:41:59     Re: BF527 ffmpeg performance

Michael Hennerich (GERMANY)

Message: 69341   

 

Check your CACHE settings (WB versus WT).

 

I can imagine you are currently using WT.

 

-Michael

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