[FFmpeg-user] Compression issue using ffmpeg

Moritz Barsnick barsnick at gmx.net
Fri Jun 12 20:59:51 EEST 2020

On Fri, Jun 12, 2020 at 16:46:30 +0000, FFmpeg user discussions wrote:

> Requesting you to read the entire email and kindly help me in solving
> this. I'm in urgent need of this fix.

This is all voluntary work here, but happy to help.

> I used the following command to convert a .mov file to .mp4 file.
> Though it's getting converted but it's not getting compressed.

> ffmpeg -i Input0.mov -y -fpre ./preset/mp4_Projector.ffpreset -astrict -2 -vsync vfr -acodec copy -vcodec copy -s 1280x720 Output0.mp4

The "copy" codec tells ffmpeg not to "compress", but instead leave the
original streams intact, as confirmed here:

> Stream mapping:
>   Stream #0:1 -> #0:0 (copy)
>   Stream #0:0 -> #0:1 (copy)

> As suggested by one of your expertise, I removed the b:v=800000 from
> the description of preset file and used the following command adding
> -crf as suggested by you:-

The point is not the preset file, the point is that you are apparently
overriding its setting with your command line.

> But, while trying the same command on another .mov file whose size
> was 562.2 MB and duration was 2h 10m 32s, it is giving error. I used
> the following command:-

> Too many packets buffered for output stream 0:1.
> [aac @ 0x7fdcc4032600] Qavg: 33517.414
> [aac @ 0x7fdcc4032600] 2 frames left in the queue on closing
> Conversion failed!

I can't help you with this, perhaps someone else can. Please try fixing your command line first.
Also please give an ffmpeg version from git HEAD a shot, perhaps your
issue is fixed there.


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