Hi.

Thanks for the explanation, I presume you used it with analogue
content (Interlaced), and with large bitrates?

About gop_size, I might be wrong of course, but doesn't it set the
interval of sending intra-frame?

So if it set it to 25 (over 10 like in example), doesn't it actually
causes FFMPEG to produce less intra-frames, and thus leaving more to
prediction, and to resulting in-accuracy/lesser quality?

Regards.

2008/8/27, Luca Abeni <[EMAIL PROTECTED]>:
> Hi,
>
>  Stas Oskin wrote:
>  [...]
>
> > I found an older post of yours (circa 2006 -
>  > 
> http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2006-February/007069.html),
>  > where you describe the following params:
>  >
>  > gop_size = 25
>  > me_method = ME_EPZS
>  > flags = CODEC_FLAG_INTERLACED_ME | CODEC_FLAG_INTERLACED_DCT
>  > mb_decision = FF_MB_DECISION_RD
>  > noise_reduction = 250
>  > pre_me = 0
>
>
> Most of those settings depend on the input video. For example:
>
>  > flags = CODEC_FLAG_INTERLACED_ME | CODEC_FLAG_INTERLACED_DCT
>
> is needed for interlaced video
>
>  > noise_reduction = 250
>   > pre_me = 0
>
>  > me_method = ME_EPZS
>  these three values were obtained by running a long set of experiments
>  and comparing the quality. They gave good results for the kind of video
>  I was using, but for other video inputs you will need different values
>  (depending on the amount of movement in the scene, the kind of light,
>  etc...).
>
>  > mb_decision = FF_MB_DECISION_RD
>
> This is the one I recommended ;-)
>
>  For what concerns the gop_size value, you can try increasing it
>  to see if the quality of the video improves (but AFAIR some players
>  have problems with large GOPs).
>
>
>
>                                 Luca
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