Live H264 decoding with DecodedOrder=1

[ABoxe]

Hello,

I would like to use the Media SDK + gstreamer plugin for h264 decode of live RTSP streams.

I am currently testing 2018 R2 release with gstreamer plugin on Windows + Skylake (HD 530)

I see a lot of dropped frames, and I see in the plugin code

DecodedOrder = 1

but this is deprecated. Does this still work ? Because I still see dropped frames when this parameters is set to 1.

Thanks

Aaron

[Dmitry_E_Intel]

Hi Aaron,

Yes, officially it's deprecated. However the code which handles DecodedOrder is not removed and, in general, should work. BTW, what is the reason you use DecodedOrder mode?  

Regards,

Dmitry

[ABoxe]

Thanks, Dmitry. I am trying to reduce latency as much as possible for a live stream. So, DecodeOrder=1 will prevent re-ordering the frames.  See also https://software.intel.com/en-us/forums/intel-media-sdk/topic/704136 for a similar constraint.

[ABoxe]

Is the SDK suitable for low-latency streaming? I understand that it is heavily multi-threaded, which may increase latency.

[Dmitry_E_Intel]

I remember that topic. I described what brings output latency in https://software.intel.com/en-us/forums/intel-media-sdk/topic/704136#comment-1907522 . Latency comes not from multi-threading but from reordering and DPB bumping logic which works according to the information from the bistream.  DecodedOrder mode indeed allows to disable this logic but it's actually a hack. This is the reason why DecodedOrder has been deprecated. On the other hand, I know that MSDK users use DecodedOrder in applications. 

Please attach the bistream where you observe dropped frames, I'll take a look.

[ABoxe]

Thanks very much, Dmitry. When I run a software decoder (libav) then there is no frame dropping, so apparently latency in software is better than hardware. But,of course, I am using GStreamer, so there are many other moving parts besides decoder.

[ABoxe]

Hi Dmitry,

Here is a capture bit stream of the live stream. I don't have access to the original bit stream

Aaron