[FFmpeg-user] dshow questions

[Moritz Barsnick]

On Sat, Aug 08, 2020 at 11:23:28 +0200, Michael Koch wrote:
> ffmpeg -f dshow -video_size 1280x720 -framerate 15 -vcodec mjpeg -i
> video="Integrated Camera" out.avi
>
> Is -vcodec in this case an undocumented option of the dshow input
> device? I ask because it's written before -i.
> Or is it an option for the output, and could (or should?) be written
> before the output file?

As other documentation indicates, "-c" ("-codec", -"vcodec") can be
either an input or an output option. As an input option, it either
tells ffmpeg which codec an input has, or in this case, it also tells
the input device which codec to choose (i.e. emit).

> Question 2:
> I have this HDMI to USB converter (which is working very good, by the way):
> https://www.ebay.de/itm/1080P-HDMI-Videoaufnahme-Video-Capture-Card-Grabber-USB2-0-Recorder-Adapter/293641909414
[...]
> [dshow @ 0000000000374800]   pixel_format=yuyv422  min s=640x480 fps=5 max s=640x480 fps=30
> [dshow @ 0000000000374800]   pixel_format=yuyv422  min s=640x480 fps=5 max s=640x480 fps=30
> video=USB Video: Immediate exit requested
>
> Why is each line listed twice? Might there be a difference between the
> lines, but FFmpeg can't show what the difference is?

I can't help you with this, sorry.

Cheers,
Moritz