[gst-devel] Help needed to reduce unusually high CPU utilization in v4l2src, caused by memory copy.

[Gibro Vacco]

Hi,

would it ber possible to mmap the memory are from the driver so that
v4l2src passes that very buffer to the remaining of the pipeline?

The only problem would be that, in case of a circular buffer in the
driver, each memory area will remain locked until the pipeline has
ended processing it.

On Thu, Jan 21, 2010 at 12:57 AM, yiliang <yiliangb at gmail.com> wrote:
>
> Hi,
>
> I am optimizing a V4L2 driver for video capture device. In the v4l2 driver,
> the DMA is performed based on frames using contingent memory buffers. After
> a frame is captured, the frame data is copied to a application buffer in
> v4l2src.
>
> gst_v4l2src_grab_frame()
>  ->     *buf = gst_buffer_copy (pool_buffer);
>
> However, the time spent on copying the buffer is very costly, about 0.01
> seconds, which is very large considering frame time is only 0.033 seconds.
>
> I do not know whether this is the right forum. Any suggestions will be
> appreciated.
>
> Thanks,
> Yiliang
>
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