[theora-dev] Encoding - CPU usage ...

David Kuehling dvdkhlng at gmx.de
Mon Oct 9 02:13:24 PDT 2006


>>>>> "Mat" == Mat  <heavensdoor78 at gmail.com> writes:

> 1.  (*) text/plain ( ) text/html
> David Kuehling wrote:
>>> Can't you grab directly in YUV ?  ( like V4L2_PIX_FMT_YUV420 )
>>> 
>> In my experience the least-common denominator for V4L2 capture would
>> be V4L2_PIX_FMT_YUYV.  Which is twice as many chroma data as YUV420.

> You can choose any colorspace you like but if you convert it to YUV I
> don't think the extra chroma data will count.

> I use V4L2_PIX_FMT_YUV420 because in this way I can use ffmpeg's
> PIX_FMT_YUV420P or ogg's OC_PF_420 directly ;) ( and also SDL overlays
> almost directly )

If that works... What I wanted to say is, that there are V4L2 devices
out there, that only support PIX_FMT_YUYV.  I had that problem with
Em2880 based USB2 video capture devices (which are doing full-speed
uncompressed PAL YUYV video over the USB bus, quite amazing!).

regards,

David
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