I believe the reason for this is that MJPEG has no standard color space because it was derived from JPEG which had no standard color space. While it's possible that this is due to the color format being reported by ffplay, I wouldn't actually put too much confidence in what it reports for MJPEG footage as it seems that ffprobe always reports BT.601 by default for MJPEG as discussed in this page:
#Obs studio webcam and stream not matching drivers
And then the mystery would be why OBS or the USB webcam drivers are interpreting it as BT.601 and why the color space setting on the input source seems to have no effect. So BT.709 would be the correct format for the USB webcam output to use in this case. BT.601 should really only be used for SD content and BT.709 should be used for HD. Why this is happening is a bit difficult to say. 1-vs-bt709įrom the screenshots posted, the overly bright green and overly dark blue and red look similar to the result of BT.709 video being interpreted in a BT.601 color space. This looks like it could be caused by a BT.601 / BT.709 mismatch issue along the lines of what is described in this page. The problem are the wrong colors, not the range. Overwriting the color range settings to 'Full' in OBS has no effect, as it is the default setting choosen by OBS.
This only increases the contrast of the picture but changes nothing to the wrong colors. It will cut away the values below 16 an the values above 235 and expand then to 0-255. Overwriting the color range settings to 'Partial' in OBS will not fix the issue. There must be a misconfiguration of the grabber hardware, or a wrong declaration of the colorspace from the mjpeg stream. And as you can see the levels do drift diffrently depending on the colortone. Originally they have all 75% or 0% as you can see on the waveform of the recording. Levels of the color bars on webcam are wrong. A color range issue would affect all colortones the same way, even the grays.Īs you can see on both waveforms, the 0% black, the 100% white, the 15% and 40% gray and the grayramp levels are correct. The stream coming from hyperdeck via USB-C is mjpeg compressed not h.264.
I dont know if ATEM mini has the same inbuilt USB-grabber. Juergen Attachments hyperdeck-recording.png (12.49 KiB) Viewed 1507 times hyperdeck-webcam.png (18.33 KiB) Viewed 1507 times I hope someone can help me, or explain to me why this happens.
I expected to get correct colors and nothing else than BT.709 from the hyperdeck-webcam.īut anyway, changing the color space settings of the webcam source in OBS from "standart" to "709" or "601" doesn't change anything. I also opend it with ffplay/ffmpeg, there it is regognized as mjpeg yuvj422p bt470bg.
#Obs studio webcam and stream not matching full
I opened the hyperdeck-webcam in VLC and VLC tells me it delivers mjpeg 4:2:2 YUV full scale in BT-601 colorspace. See rgb-waveform on bottom of atached files to compare. Recording in hyperdeck has correct values. On webcam green levels do obviosly not match to the right values, blue and red also, but not that much. I just bought a Hyperdeck studio HD mini and i am trying to use its option to act as a webcam to OBS.
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