[MEncoder-users] new doom9 codec comparission

[Corey Hickey]

Michael Niedermayer wrote:
>>>I can only conjecture as to why they are different and which one is
>>>correct; the only thing I am pretty sure about is that
>>>mplayer/mencoder decodes the DVD that way -- it doesn't get altered
>>>during the encoding process.
>>
>>The doom9 shot has clearly been cropped, sized and aspected so why
>>not gammaed too? I'd guess it's a screenshot so it's been
>>postprocessed by whatever is playing it.
>>
>>Interestingly, when I play your clip in mplayer (vo x11 without
>>postpro) it does not appear quite as dark as your frame does. It
>>could be an optical illusion due to the movement though.
> 
> 
> an additonal source of brightness change is that jpeg and mpeg use
> different ranges for the luma component, and IIRC mplayer&mencoder 
> ignore this, probably most other tools too, i think ffmpeg doesnt.
> also keep in mind that xv & x11 tend to look different on many
> grafic cards

For me, xv, x11, png, and jpeg all looked the same.

Doom9 told me that it was probably due to the windows programs
displaying the video more brightly, and, as long as the encoded video
has the same brightness as the original, I shouldn't worry about it.

-Corey