[FFmpeg-user] screen capture - small files

[Jannes Faber]

I'm using this, although I'm not going for the smallest output:

$FFMPEG -hide_banner -loglevel warning -video_size ${W:-1280}x${H:-1024} \
 -use_wallclock_as_timestamps 1 -framerate 30 \
 -f x11grab -i :0.0 \
 $ALL_AUDIO_INPUTS \
 $ALL_MAPPINGS \
 -codec:v libx264 -pix_fmt yuv444p -qp 0 -tune stillimage -preset ultrafast
-profile:v high444 \
 -codec:a copy \
 $OUTPUT_FILE

You want to have a look at the -tune and -preset options.


--
Jannes

On 23 November 2015 at 08:27, Jesper Hedin <jesper.hedin at intaktus.se> wrote:

> Hello all.
>
> I want to use ffmpeg to capture screen and sound on a macintosh. I want
> the file size as small as possible, with a fps of about 3-5 and audio
> quality of maybe 128 kbps at most, though 64 kbps is acceptable.
>
> This is the closest I have come:
>
> ffmpeg  -f avfoundation -i "1:0" -c:v mpeg4 -c:a aac -strict -2 -r 3 -b:v
> 1024 out.mp4
>
>
> It gives me a large file size and very good audio (too good/better than
> needed). Also a few messages appear that I don’t understand:
>
> [avfoundation @ 0x7fc535000000] Selected pixel format (yuv420p) is not
> supported by the input device.
> [avfoundation @ 0x7fc535000000] Supported pixel formats:
> [avfoundation @ 0x7fc535000000]   uyvy422
> [avfoundation @ 0x7fc535000000]   yuyv422
> [avfoundation @ 0x7fc535000000]   nv12
> [avfoundation @ 0x7fc535000000]   0rgb
> [avfoundation @ 0x7fc535000000]   bgr0
> [avfoundation @ 0x7fc535000000] Overriding selected pixel format to use
> uyvy422 instead.
> [avfoundation @ 0x7fc535000000] Stream #0: not enough frames to estimate
> rate; consider increasing probesize
>
> The pixel format used is uyvy422. If I explicitly choose it,the output
> becomes
>
> Incompatible pixel format 'uyvy422' for codec 'mpeg4', auto-selecting
> format ’yuv420p'
>
> and
>
> [avfoundation @ 0x7f9c24800000] Overriding selected pixel format to use
> uyvy422 instead.
>
>
> So does anybody have a tip for me on how to use ffmpeg to achieve my goal?
> Thanks!
>
>
>
>
>    …Jesper
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