[FFmpeg-user] Copy from mjpeg USB camera stream to file

[Moritz Barsnick]

On Wed, Jul 26, 2017 at 01:21:36 +0300, Aviv Hurvitz wrote:

> I want to copy the original stream without any transcoding or
> processing.

Please explain your definition of processing. That's what ffmpeg does.

> frame=   56 fps=8.0 q=-1.0 Lsize=    4470kB time=00:00:06.89
> bitrate=5306.9kbits/s speed=0.989x
> video:4455kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB
> muxing overhead: 0.343590%
> 
> Note on the last line my fps=8.0 while the input is 30 fps. How can I fix
> this?

Hmm, on the other hand, "speed=0.989x" indicates that ffmpeg appears to
be encoding in real time. Perhaps your camera is only delivering 8 fps,
despite the setting. Are you operating in very low light? (Sorry, I
know very little about dshow and how it interacts with cameras. I think
I recall that cameras under Linux/V4L could expose the same behavior.)

Moritz