[gst-devel] Getting access through custom buffers through subbuffers

[Demon Deng]

I think it is better to write your own videorate plugin or modify videorate
plugin to support DMAI buffer than modify gstbuffer.

2010/3/16 Arnout Vandecappelle <arnout at mind.be>

>  Hoi all,
>
>  I'm currently hacking with the DMAI plugins that use the DSP on the TI
> OMAP
> for video encoding and other transformations.  These plugins require
> specially allocated DMA buffers to be able to communicate with the DSP.  A
> custom GstTIDmaiBufferTranport sub-class of GstBuffer is used for that.
> When the encoder element receives a buffer, it checks whether it is a
> GstTIDmaiBufferTransport; if not, it memcpy's the data in a DMA buffer.
>
>  Since the memcpy's completely kill performance in my application, I make
> sure that GstTIDmaiBufferTransport buffers are allocated in the beginning
> of
> the pipeline.  However, when I insert a videorate element in the pipeline,
> it creates subbuffers of these.  These are no longer recognized as
> GstTIDmaiBufferTransport objects, and therefore the physical address of the
> DMA buffer is not accessible.  Hence, there are memcpy's again.
>
>  To work around this, I've added a function to GstBuffer that checks if it
> is a subbuffer and if so returns the parent buffer.  Does this sound like a
> good solution?  If so, I'll put it in bugzilla.
>
>  Regards,
>  Arnout
> --
> Arnout Vandecappelle                               arnout at mind be
> Senior Embedded Software Architect                 +32-16-286540
> Essensium/Mind                                     http://www.mind.be
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>
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