Intel Quick Sync related

[Ankush_W_]

I have a few questions to ask some of which might be pointless but let me know even if they mean nothing

a) Can I use a single MFXVideoSession object for creating a MFXVideoDECODE and MFXVideoVPP objects?
b) And if I had to deocde multiple streams simultaneously then do I need to create multiple MFXVideoSession objects, like one for each stream? If yes then possibly how many can i create considering the streams to be HD(1920x1080) 30fps on a i7 4gen?
c) And do I need to allocate the surfaces seperately for each stream, because if i am trying to decode 5-6 streams along with colour conversion using vpp and I am allocating surfaces for each one seperately then the memory usage shoots up. Is there a way to fix it?

Thank you.

-Ankush

[Jeffrey_M_Intel1 · Accepted solution]

Hi Ankush,

a) a session can contain one each of decode, VPP, and encode.  You can choose the combination.  Decode only, encode only, VPP only, Decode+VPP, VPP+encode, decode+encode, etc.  Multiple sessions can also work together.

b) to decode multiple streams you would need multiple decoders in multiple sessions.  Assuming no corner cases like large decode -> resize -> small encode, decode tends to be the least expensive part of the pipeline.  Since Media SDK is asynchronous the decode time can be "hidden" in other pipelines.  We don't have a lot of data for multiple decodes since the decode itself is usually not the bottleneck.  You can see for yourself how many FPS your system can decode with sample_decode specifying no output file.  (You will want to use the HW implementation and video memory though.)   Timing multiple processes of the decode sample should give you a reasonable estimate of how many an application with your specific hardware can handle in real time.

c) For each session you will need to query the surfaces needed.  If memory is a concern, async depth is probably the easiest way to minimize memory use.  Asynchronous implementation and higher async depth is important for single stream performance.  For multiple streams you can still get good performance with minimized memory footprint using async depth=1.

Regards, Jeff

[Ankush_W_]

Hi Jeffrey

Thank you so much for the quick reply and the your answer was very helpful for getting things clearer.

Thank you much once again Jeffrey.