[gst-devel] GPP + DSPs

[David Bourgoyne]

Felipe Contreras wrote:
> On Sun, Oct 5, 2008 at 7:27 PM, David Bourgoyne
> <dbourgoyne at austin.rr.com> wrote:
>   
>> Felipe Contreras wrote:
>>     
>>> On Fri, Sep 26, 2008 at 5:35 AM, David Bourgoyne
>>> <dbourgoyne at austin.rr.com> wrote:
>>>
>>>       
>>>> Felipe Contreras wrote:
>>>>
>>>>         
>>>>> On Wed, Sep 24, 2008 at 9:50 PM,  <dbourgoyne at austin.rr.com> wrote:
>>>>>
>>>>>
>>>>>           
>>>>>> Hi all,
>>>>>>
>>>>>> I'm considering using GStreamer for an application is which GStreamer will span a GPP and multiple DSPs.  The GPP and DSPs are connected via PCI.  So GStreamer will have to proxy buffers and messages across the PCI bus.
>>>>>>
>>>>>> Can you point me to documentation, info, case studies, etc. that will help me to architect this solution?
>>>>>>
>>>>>>
>>>>>>             
>>>>> What kind of DSP/GPP?
>>>>>
>>>>> We can propose different ways to do it at GStreamer level, but
>>>>> ultimately you would have to communicate with the hardware, is there
>>>>> code that is doing that already?
>>>>>
>>>>>
>>>>>
>>>>>           
>>>> Assume an OMAP DSP with gst-openmax.  A GPP running Linux uses v4l as a
>>>> gstreamer src and needs to send buffers to the OMAP DSP to be encoded
>>>> which then sends buffers back to the GPP for transmission over
>>>> ethernet.  There needs to be a gstreamer proxy (marshalling) that
>>>> connects the GPP GStreamer Bin to the OMAP DSP GStreamer Bin.
>>>>
>>>>         
>>> Well, that's the answer isn't it?
>>>
>>> gst-openmax is a good example of how to communicate with an
>>> asynchronous subsystem (dsp), in this case through the OpenMAX IL API.
>>>
>>>
>>>       
>> Maybe you could elaborate.  Let's take the case of the OMAP.    I have a
>> main GStreamer application running on a GPP.   On the OMAP device I have
>> gst-openmax running on the ARM and the actual codec running on the DSP
>> abstracted by OpenMax.
>>
>> My question is how do I connect the GStreamer pipeline on the GPP to the
>> GStreamer pipeline on the ARM seamlessly.  Control and bitstreams will
>> have to be transfered over PCI, and video perphaps over PCI or Video ports.
>>
>> Has there been thought in the GStreamer community how to bridge this
>> heterogeneous design, or is this something I have to invent.
>>     
>
> This is a little bit confusing. ARM is a GPP, maybe by GPP you meant
> an x86 machine? If that's the case then you want to connect an ARM
> processor to an x86 one?
>
>   
Yes, think of it as a Master x86 GPP with several OMAP (ARM+DSP) devices 
all connected via PCI.  The v4l source may be on the x86 and an encoder 
on the OMAP device.  I have to create a GStreamer pipeline on the x86 
and hook it to a OMAP pipeline and then back to an x86 pipeline to send 
the compressed bitstream over ethernet.


David