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

Ute Willmore uwillmore at remotegeo.com
Wed Jul 26 21:59:26 EEST 2017

Thanks Gyan!
You are a life saver! I really want you to know how grateful I am that you
helped me with this problem. I had tried so many different ways to get this
solved and got nowhere. I asked for help on the superuser group, but got
none. I tried different converters but it seemed there was always a

For example: I tried again to do this with VLC yesterday when I couldn't
figure out how to do it with mp4box. I found the command to extract the
video from the avi file rather quickly but could not get the audio
extracted. I found examples for extracting audio from an avi file, but they
never worked for me. There is a way to convert an avi file into an mp4 file
in a single step, called a "Dump", using the GUI. After hours of trying to
reproduce the results on the command line, I gave up.

Of course, if I had looked at your original post again, I would have seen
the command to get the audio using ffmpeg, but I had been reading the
mp4box documentation and found the command to extract the raw video. I
recognized it as the one you used in your first reply. I also saw commands
for getting Audio but again, I could not get it to work. Well, maybe that
wasn't for mp4box. :-) I have tried to many tools and read so much online
documentation it is hard to recall what I found for what tool. :-)

Anyway, I wanted to do this is as few steps as possible using a few tools
as possible, which is why I didn't even think of using ffmpeg to get the
audio and combine audio and video. But, the solution you provided will do.
If my supervisor doesn't like it, he can try to figure out something else.
:-) I think he will be very happy though. He tried to solve this for days,
before he assigned the task to me.

*Would you mind if I posted your solution on the super user group?* I just
want other users of ffmpeg to have this solution available to them. It
could save someone a lot of time and frustration.
I will also include the bug report Carl Eugen Hoyos filed.

*I will of course give you credit for finding the solution.*

Again, thank you very much for your help! You have been awesome!!!


On Wed, Jul 26, 2017 at 10:38 AM, Gyan <gyandoshi at gmail.com> wrote:

> On Wed, Jul 26, 2017 at 9:50 PM, Ute Willmore <uwillmore at remotegeo.com>
> wrote:
> > That helps, but I don't see the second command to get the audio or use
> > ffmpeg to play the video.
> >
> The 2nd command in my original post (where I presented this method).
> It is,
> ffmpeg  -v verbose -i hd_video.h264 -i hd.avi -map 0 -map 1:a -vf
> scale=640:480 out.mp4
> Gyan
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