[MEncoder-users] mencoder size and aspect ratios for H.264 video

[John Ratliff]

>
> Well, --aspect-ratio refers to a stream ID, so that shouldn't matter
> where it is located in the cmdline. I though that you used
> --aspect-ratio 16:9, which will put AR 9 on stream 16.
>
>   
I think that was the first thing I tried, but it was ignored as I put it
at the end of the command line. Trying it now at the front, I get this:

"Warning: 'video.x264': A track with the ID 16 was requested but not
found in the file. The corresponding option will be ignored."

I think because the stream ID refers to the video input file, not the
matroska stream it will become. I know the -A option must come before
the video.

>> harddup is for audio/video sync. I don't know if it it always necessary,
>> but I'm afraid to change things that work.
>>     
>
> I use this filter only when needed (-of mpeg for instance), and most of
> the time, I have no problem with AV sync.
>   
I may try a dropping this.

>   
>> I want to scale the movie to reduce filesize and to ensure I have a 16:9
>> ratio. Do you think this is a bad idea? If so, why?
>>     
>
> Going from 720x352 to 640x360 doesn't decrease much the number of
> pixels, and would spread the artifacts introduced by the first encoding
> (to DVD video), leading to adding more artifacts than if you don't
> scale. About the aspect ratio, as it is specified in mkv, or directly in
> x264 bitstream using dsize vf as RC told, all readers should resize the
> video correctly, often using accelerated scaling.
> However, I'm far from being a video guru, and I cannot answer a clear
> yes or no, I just would not do scaling here.
>   
That seems reasonable. Perhaps I will stop scaling my videos.

>   
>> I took all the x264encopts from an article I read on the web. I have no
>> idea what any of them are. You're saying I don't need and shouldn't use
>> turbo on the second pass?
>>     
>
> Read the man mplayer, go to the -x264encopts part (use '/' to search),
> and lurk a bit. I think you're not commited to understand everything,
> but it gives good terms to search for over the web.
> About turbo, it says it is intented for first pass only (or everything
> else the last pass).
>   
I gave up reading those options after an hour or so. I'm happy with the
quality and speed for now. I will remove turbo from the second pass though.

Thanks,

--John Ratliff