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

[Carl Eugen Hoyos]

James Board <jpboard2 <at> yahoo.com> writes:

> >> libx264 is one of the best AVC encoder available.
> >
> >As said, this is not correct, different independent 
> >tests have shown that no matter how much money you 
> >spend, you will not get a better encoder.

> I don't know what you mean.  Is this more correct?
>     libx264 is the best AVC encoder available

This is correct.

> Or is this correct?
>     libx264 is the best encoder available

I don't know how mature the available HEVC encoders 
are, but it is possible.

> or this?
>     There are better AVC encoders available

Isn't this the opposite of what I wrote above?
(Sorry, I am not a native speaker.)

[...]

> I use mencoder to 2-pass-encode AVI files with vcodec=mpeg4
> at a bitrate of 10,000,000 bits per second.  I have tried to
> get ffmpeg to do the same, but either failed

Please report this.

> or it was slower.

This is quite unlikely.
(Consider particularly that MPlayer does not automatically 
use multi-threading.)

> Feel free to offer an example way of doing this with ffmpeg.
> 
> Also, I plan on using mencoder and libx264 to produce MPEG-4
> AVC files and 422-format pixels.  Can ffmpeg do this?

(Was this meant seriously? Very, very hard to believe.)

> >(And concerning your current task: FFmpeg contains 
> >code that makes sure that no chroma samples get 
> >lost if the filter chains allow it as in your case.)
> 
> I'm not 100 percent sure what this statement means.

The problem that made you starting this thread was that 
you didn't manage to force MEncoder with "format" to use 
the colour space you want to reduce quality loss. FFmpeg 
by default tries to use a colour space that avoids this 
loss. (And it supports a similar format filter if you 
want to force a colour space.)

> I still have problems with 'blue' pixels when converting from
> ffhuff-compressed AVI files with yuv422 pixels to non-compressed
> AVI files with yuv422 pixels. 
> I never saw a response to that issue.

You had not reported it in a way that allowed me to 
reproduce this problem.
(You still haven't but I finally found out what the 
problem was.)

Carl Eugen