MPEG-2 userdata mfxPayload limitations

[andrasjpeg]

How much userdata can I store and how many mfxPayloads?

It seems like there is a 1KB limit on payload size, and I can only specify one payload.

For example, if I specify several smaller payloads (in mfxEncodeCtrl), the decoder will only return the first one. After the next call, numBits will always be zero...

Andras

[Anthony_P_Intel]

Hi Andras,

I believe you have the right expectation and you may be seeing an issue in the decoder handling of MFXVideoDECODE_GetPayload for MPEG-2 streams. If the encoded stream has 2 payloads, then you should be able to call MFXVideoDECODE_GetPayload twice while decoding and payload->NumBit should not be 0 (until a 3rd call is made).

Is the MFXVideoDECODE_GetPayload call returning any error or warning?
Do the payload->Type or BufSize fields look valid?

I will investigate.

-Tony

[andrasjpeg]

I do not get any errors or warnings from GetPayload. I am calling it in a loop, unitl it returns 0 NumBit. The problem is: The second call of GetPayload will always return 0 for NumBits, even though there should be more data. I am not sure if the issue is in the encoder not writing more than one payload, or the decoder not returning more than one..

[andrasjpeg]

Any thoughts on this? Is there anything I can do to help verify the problem?

Thx,

Andras

[Petter_L_Intel]

Hi Andras,
sorry for the delayed reply.

We revisited this topic by creating a similar setup as you describe. I'm sorry to say but as you point out there seem to be issues with the way payload handling for MPEG2 operates. Thanks for making us aware of this.

We are currently investigating how to resolve the issues.

In the meantime would it be possible to limit your payload size to 1KB and a single payload? If not, can you please explain in more detail how this impacts your implementation.

Regards,

Petter

[andrasjpeg]

Hi Petter,

I cannot limit the payload size to 1KiB. For now, I'm storing the payload separately from the video.

Thx,



Andras