[FFmpeg-user] Poor quality output when converting avi to mp4

[Gyan]

On Tue, Jul 25, 2017 at 1:10 AM, Ute Willmore <uwillmore at remotegeo.com>
wrote:

>
> What is non-standard about my input video?
>

That I don't know. Only that ffmpeg doesn't decode most of the frames from
the original file.


> I ran many conversion commands, and listed several of them in my original
> message. Which one did you use?
>

'ffmpeg  -v verbose -i hd.avi -vf scale=640:480 scaledoutput.mp4'

What does "Muxing to TS" mean and why/how did you do that? What does
> "Invalid NAL warnings mean?
>

H.264 data is stored in chunks called NAL units. I transferred the contents
to another container format just to test the result, so you can ignore this
part.



> Is this the one you are using?
> https://www.videohelp.com/software/MP4Box
>

Yes, but this is the download page at the official site:
https://gpac.wp.imt.fr/downloads/gpac-nightly-builds/

mp4box is one of the tools bundled.


> Do you have any idea what needs to be done to
> produce a standard avi video in the first place?
>

How are these AVIs produced?