v4l2src on rtsp-server

[Gary Thomas]

On 2013-07-09 19:02, jlancaster wrote:
> After more debug time, I think I am noticing some problems with the
> initialization of one of my OMX elements in the top level bin of the rtsp
> server.
>
> For example the following pipeline works great from the command line:
>
> gst-launch -e -v v4l2src device=/dev/video0 always-copy=false queue-size=8 !
> 'video/x-raw-yuv-strided,format=(fourcc)NV12,width=640,height=480,framerate=(fraction)30/1'
> ! omxbufferalloc numBuffers=8 ! omx_h264enc ! rtph264pay name=pay0 pt=96 !
> gstperf ! udpsink host=192.168.0.186 port=5000
>
>
>
> However the following pipeline is used as the top level bin in the rtsp
> server:
>
> "(v4l2src device=/dev/video0 always-copy=false queue-size=8 !
> 'video/x-raw-yuv-strided,format=(fourcc)NV12,width=640,height=480,framerate=(fraction)30/1'
> ! omxbufferalloc numBuffers=8 ! omx_h264enc ! rtph264pay name=pay0 pt=96)"
>
> When I run the server and pull video using VLC I do not see omxbufferalloc
> initialize and set properties at all.
>
> I am assuming I need to fix the omxbufferalloc element, but I am not clear
> why it works with gst-launch and not with the rtsp server.
>
> What are some possible reasons why an element (speaking in general terms) in
> the top level bin in the rtsp server not initialize but runs fine using
> gst-launch?

I had trouble with any pipelines that included quoted strings when using
the RTSP server.  Try leaving those out, e.g.

"( v4l2src device=/dev/video0 always-copy=false queue-size=8 !
video/x-raw-yuv-strided,format=(fourcc)NV12,width=640,height=480,framerate=(fraction)30/1
! omxbufferalloc numBuffers=8 ! omx_h264enc ! rtph264pay name=pay0 pt=96 )"

Notice I put spaces around the () - that also seemed to help a bit.

The real problem is that the code is quite silent about errors (or at least
things it doesn't like) when those pipelines are being parsed.

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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