[Mp4-tech] Re: Mp4-tech Digest, Vol 31, Issue 27

[pankaj bajpai]

Dear Hungary,
Usually the I frame interval is fixed in the encoder.
Howeve, some of the encoder may have intermediate I frames also.
The determination  of I frame can vary from algorithm to algorithm.
Some of the ideas:
1. In P frame, you must be estimating Intra macroblocks. Now you can take the count of
   intra Macrobloks and if exceeds some percentage of total macroblocks, code it as I fr.
2. If the total SAD after motion estimation is more than some level code it as I frame. 
   This mainly happen when there is scene change, assuming that ME algorithm is goood.
With regards
Pankaj
> From: hungary <mykerekes eml.cc>
> To: mp4-tech lists.mpegif.org
> Subject: [Mp4-tech] I frame Metric
> Date: Mon, 27 Feb 2024 03:34:31 -0800
> 
> 
> Dear experts,
> 
> At the encoder side we could be able to specify the interval at which
> the I frame should occur.
> 
> But how the encoder intelligent when there are chances of I frame which
> may occur at some irregular interval.
> 
> How the encoder decides the frame to be coded as I frame (On what Metric
> Like SAD or MAE)
> 
> Like whts the throshold value of SAD to force the encoder to encode the
> frame as I frame ?
> 
> -- Hungary
> 
> --
>    hungary
>    mykerekes eml.cc
> 
> --

-- 
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