[MPlayer-users] Produce 422 format pixels with mencoder for mpeg4-encoding

James Board jpboard2 at yahoo.com
Thu Dec 12 19:04:34 CET 2013

>> Does anyone have an opinion on the quality of MPEG4 video produced

>> by x264 as compared to libav?  By itself, 422-format pixels are higher
>> quality than 420 pixels.  But if the x264 codec itself isn't as good as libav,
>> then the overall quality might be better with 420-format MPEG4 libAV,
>> then with 422-format MPEG4 from the x264 codec.  Does anyone know?>
>Where are you getting that x264 is a "worse codec" than libav's
>"mpeg4" encoder.

I didn't say x264 is a "worse codec".  Where did you get "worse codec" and
why did you quote it?  It wasn't in my message.  I merely asked if anyone
had an opinion on x264 quality vs libav quality.

>and they aren't codecs, they are encoders that encode to a specific codec)?

From Wikipedia: A codec is a device or computer program capable of
encoding or decoding a digital data stream or signal.  

>In my opinion MPEG-4 AVC always produces better results than MPEG-4
>ASP for a given bitrate, almost regardless of any other options.
>MPEG-4 AVC is the basis of almost all HD broadcast television, all HD
>disc contents, almost all live streaming, and almost every "scene"
>(pirate) release.

The quality of the MPEG-4 AVC video would be highly dependent
on the quality of the encoder that produced it.  Same is true for MPEG-4
ASP.  I'm asking about the quality of the video produced by libx264 (with
422 pixels) vs the quality of the video produced by libav (with 420 pixels).
Does anyone have an opinion on whether or not one is better than the other?

>ISTM that pairing a less advanced and effective encoder with less
>chroma subsampling is unlikely to produce higher quality results.

Which encoder is  less advanced and less effective?  x264?  or libav?

>If you're doing this for post-production, you should probably use very
>high bitrate (even uncompressed) MPEG-4 AVC for your intermediate
>files, before producing whatever output you finally want.

My intermediate files are lossless-compressed with ffvhuff.  The final output
file is MPEG4.  I know nothing of ASP or AVC or whatever the difference
is between them (but maybe I should learn).


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