Opened 2 years ago

Last modified 2 years ago

#6279 new enhancement

can't request rgb24 (uvc over dshow, unknown compression type)

Reported by: Djfe Owned by:
Priority: wish Component: avdevice
Version: git-master Keywords: dshow
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no


ffmpeg doesn't seem to know some of the color space id's that dshow uses.
In particular the rgb24 color space:
"[dshow @ 0000000000756320] unknown compression type 0xE436EB7D min s=1920x1080 fps=15 max s=1920x1080 fps=59.9999"
(I provided a log output, containing more similar lines)

A quick google search for the id (0xE436EB7D) in question reveals, that it represents rgb24:

I bet ffmpeg doesn't know the other RGB GUIDs either, but I can't verify it, since my device only supports outputting in those two color spaces.

I'm unsure if it is allowed to simply take the information from the linked opencv file (regarding the opencv license (vs LGPL)) though.
But it would be nice if other GUIDs apart from rgb could be "imported" into ffmpeg's knowledge as well.

But now to the interesting part:
is it enough if ffmpeg knows, that the data is of color space rgb24, or not?

until someone finds the time: I'm looking forward to rgb24 support for uvc over dshow :) (maybe that will give you some motivation )
The reason being, that I'm recording to qtrle (lossless, but only rgb color space).
Asking the grabber to give me rgb avoids unneccessary color space conversion on both sides.

I'm unsure if the type of this bug report is a defect or an enhancement,
feel free to correct it, if you think it isn't a defect ;)

Attachments (2)

ffmpeg-20170330-204303.log (10.9 KB) - added by Djfe 2 years ago.
ffmpeg report log; device: Magewell USB Capture HDMI (it does HDMI -> USB 3.0 -> UVC)
patchdshowguid.diff (619 bytes) - added by cehoyos 2 years ago.

Download all attachments as: .zip

Change History (4)

Changed 2 years ago by Djfe

ffmpeg report log; device: Magewell USB Capture HDMI (it does HDMI -> USB 3.0 -> UVC)

comment:1 Changed 2 years ago by cehoyos

  • Component changed from ffmpeg to avdevice
  • Keywords dshow added
  • Priority changed from normal to wish
  • Type changed from defect to enhancement

Please test attached patch.

Changed 2 years ago by cehoyos

comment:2 Changed 2 years ago by Djfe

Thx for your quick answer, I'll do that.
I only have to setup an environment for compiling ffmpeg on windows now
so I'll reply in a few hours/tomorrow when I'm done.

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