encoding efficiency in decoding order

[OTorg]

HI!

How coding efficiency degrades when using the decoding order?

Can encoder convert to I frame specified as P by client (scene change detection) in this mode, etc?

[Surbhi_M_Intel]

Hi there, 

Thank you for your question. I was wondering if you have any analysis done to show that the encoding performance decreases when using encoding order?
For scene change detection there are few options -

• Please check Pg 4 of MediaSDK manual, where it is mentioned that display order changes the GOP sequence.
• Look Ahead Rate control method can also help us to get better results for scene change detection. More details can be found at  Pg 38 in MediaSDK manual.
• Another thing you can look at is AdaptiveI and adaptiveB, flag controls insertion of I and B frames, details can be found at Pg 85 of Media SDK Manual.

Let us know if these options help or if your need is different. 

Thanks,
-Surbhi

[OTorg]

Sorry for being unclear in terms. I asked about the encoding quality, not performance degrade in decoding order.

So, paraphrase: is AdaptiveI/AdaptiveB algo applied by encoder in decoding order mode? Can it encode as MFX_FRAMETYPE_I frame pushed to EncodeFrameAsync() with MFX_FRAMETYPE_P sign, eg? Are there any intelligent algorithms applied by encoder in presentation order, but not available in decoding order?

[Surbhi_M_Intel · Accepted solution]

Hi dj_alek,

As far as I am understanding this is that the difference btw both order is that how we feed the data to our encoder. With display order, encoder reorganizes the data and process it in encoding order where as when we send the data in encoder order data can be directly fed.
To answer your question direct there is no intelligent algorithm which can be applied to display order but not to encode order. The only way I could think of increasing the quality is using Look Ahead BRC mode, if you don't want to set QP per frame. 
Just checked with the experts regarding AdaptiveI and AdaptiveB, currently this mode is not supported. 

Thanks,
-Surbhi
 

[OTorg]

Thanks!