Re: question for soc-camera driver

[Guennadi Liakhovetski <g.liakhovetski@xxxxxx>]

On Fri, 16 May 2008, ·ëöÎ wrote:

> 2008/5/15 Guennadi Liakhovetski <g.liakhovetski@xxxxxx>:
> > 2008/5/15 Guennadi Liakhovetski <g.liakhovetski@xxxxxx>:
> > What is your <struct pxacamera_platform_data>.mclk_10khz set to? What
> > kernel version are you using? I do not know what you do in your FPGA, are
> > you sure it doesn't modify your camera bus timing (pixel clock, VSYNC,
> > HSYNC, master clock)?
> 
> mclk_10khz=1000,and I try 800,500. And the number of dropped frames do
> not decrease with lower frequencies. kernel I used is linux-2.6.24.
> And I sure FPGA doesn't modify my camera bus timing.

Strange, that dropped frames do not decrease. But you do see, that frames 
are generated at a lower rate? You can also try 2000 for comparison.

> > I assume, you write to the filesystem from another thread, right? And the
> > writer thread just blocks on write(). What does your grabber thread do at
> > this time? Can it continue processing video buffers and queuing new ones
> > or it waits for the writer thread?
> 
> yes, I use another thread to write a file.when I write a file to
> Norflash,overrun will occur until writting is over.My grabber thread
> waits for the writer thread at this time.

This is certainly wrong. Your grabber thread must continue collecting
completed and supplying new video buffers to the driver. If your writer   
thread is not fast enough, you should drop frames between your two
threads.
  
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer

--
video4linux-list mailing list
Unsubscribe mailto:video4linux-list-request@xxxxxxxxxx?subject=unsubscribe
https://www.redhat.com/mailman/listinfo/video4linux-list