[FFmpeg-user] dshow questions

[Michael Koch]

Am 08.08.2020 um 13:41 schrieb 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).

Thanks for your answer, that makes sense.

>> 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.

I see the same behaviour also with the built-in webcam in my notebook. 
All lines are listed twice.

Michael