I'm trying to digitize some VHS tapes (presumably recorded as NTSC), but I have some questions that I've yet to find answers for. My current process/setup is as follows:
- VHS tapes are played in a PV-D4745S-K VCR
- The VCR's composite output is captured using a generic EasyCap capture card.
- The captured output is fed into OBS Studio with the following settings:
- A source with it's device set to the capture card, the video format is set to
YUYV 4:2:2, the resolution is set to720x480, the frame rate is currently set toLeave Unchanged(more on this later). - Under
Settings>VideoI have setCommon FPS Valueswith29.97. - I also have set my encoding options under
Settings>Output, as well as audio settings underSettings>Audio, but the details of that aren't relevant in this context. - I also have deinterlacing disabled by right clicking on the scene and selecting
Deinterlacing>Disable.
- A source with it's device set to the capture card, the video format is set to
With this, I seem to be able to capture VHS tapes with decent quality, but I have some nagging questions:
- How do I verify if OBS has indeed captured interlaced? I'm trying to capture both fields, but I'm unsure if that's actually happening, and I'm not sure how to go about verifying it.
- Should I capture at 29.97 FPS or 59.94 FPS? My thinking is that, given that I'm capturing interlaced, I would think I would multiply the number of captured frames by 2 as, if I understand correctly, each captured frame contains 2 fields, and each would be captured sequentially, so if I want to capture at 29.97 FPS interlaced, I would need to capture at 59.94 FPS. I'm not sure if I'm right about that though.
- I mentioned above that the framerate under the source properties is set to
Leave Unchanged. The reason for why I chose that option is because the only other options that it offers for framerates are30.00,20.00,10.00, and5.00— ie there is no option for29.97, nor59.94— so I'm usingLeave Unchangedin the hopes that it's autodetecting the proper frame rate, but that's mostly an assumption on my part. The closest to NTSC's29.97would be30.00, but I'm not sure if this is an issue. And what's confusing me more is that I have29.97FPS set underSettings>VideowithCommon FPS Valuesand29.97set. If I set to source framerate to 30 with OBS at 29.97, will that lead to syncing issues? Is there a way to force the source to use 29.97 to match OBS? What's confusing me further about this is that if I list the formats for the capture device with
I get the following output (I have truncated it to only list what's relevant, as the full output is long and contains unnecessary information):v4l2-ctl --device=/dev/video2 --list-formats-ext
There is no option for 29.97 FPS, and, as can be seen by the output, it matches what OBS sees. Is this an issue? It seems, to me, that the capture card isn't capable of proper NTSC framerates, and can only capture at 30 FPS as the closest value.[…] [0]: 'YUYV' (YUYV 4:2:2) size: Discrete 720x480 […] Interval: Discrete 0.033s (30.000 fps) Interval: Discrete 0.050s (20.000 fps) Interval: Discrete 0.100s (10.000 fps) Interval: Discrete 0.200s (5.000 fps) […]
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