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1 point

2 months ago

This was very informative! Thank you for your comment!

you should check that the video output is actually at [59.94 Hz]

How does one measure the input frequency of the video feed? I’m not aware of OBS being able to monitor the frequency/refresh-rate of individual input devices, but I could certainly be wrong.

Don’t use the converter if it cannot output 480i or at the very least 480p! Scaling should happen during playback, the files should be original resolution.

I looked on Amazon again, and it seems that every converter being sold only outputs 720p, or 1080p — none of them simply repeat the input resolution, eg 480p or 480i. Would you have a converter in mind that would accomplish this?

I’d just clean the VCR after every tape if I suspect mold. You’d still need to clean the cleaning VCR after every tape to avoid cross-contamination

Do you have any resources that you would recommend for proper cleaning of a VCR?

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ChaoticNeutralCzech@feddit.org

[ - ]

2 points

2 months ago

Get an actual composite capture card for the job. HDMI converters are passable for displays and not much else, especially if they insist on scaling to HD. Most generic capture cards will output the correct, interlaced video to your PC. Check community reviews online by people who know what interlacing means. As for a question in your other comment, you then need to check that your software’s video output is interlaced and the correct resolution and frame rate. I use ffprobe (CLI) or MediaInfo (CLI/GUI) to check this.

The composite signal frequency will be either 50 Hz (SECAM or PAL) or 60000/1001 Hz (NTSC), depending on your region. Some later PAL decks have NTSC playback but you won’t see home NTSC recordings in PAL countries and vice versa unless your family moved. A good capture card driver will let you pick between these three standards and even tell you how many lines of video have been detected. However, this is not necessary as many capture cards will autodetect everything. If the resulting video is B/W, it’s probably an incorrectly set standard (NTSC and PAL encode color slightly differently (PAL is more complicated but more robust) while SECAM does its own very different thing), in which case you MUST find these settings and change them.

As for cleaning the VCR, I’d just buy a cleaning tape and “play” it for 20-30 seconds, never using the same section twice. If it’s supposed to be wet-cleaning and the isopropyl alcohol has dried up, you need to replenish it - check the attached instructions - and then give the isopropyl-cleaned mechanism a minute to dry up before inserting a videotape! Some people clean heads manually but I’m afraid I’d leave a hair or piece of cotton in the finicky mechanism and ruin everything.

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[ - ]

1 point

2 months ago

Get an actual composite capture card for the job.

Ha, honestly, I wish that I would’ve done this to begin with. It’s way cheaper, and simpler to get the one composite capture card rather than converting composite to HDMI, then capturing HDMI. I’m honestly not entirely sure why I did the latter — perhaps it’s because I was under some presumption that such a device wouldn’t exist (which, now, I realize is an obviously silly assumption to make). I found this one. It’s still just a generic capture card, but it’s a direct composite capture. Do you think that it would suffice?

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ChaoticNeutralCzech@feddit.org

[ - ]

2 points

2 months ago

Hmmm… It seems to be an EasyCAP clone, there are several devices in this form factor with different chipsets. As far as I’ve looked, they all will stream lossless interlaced video and it’s up to you how to handle it. The “720p” claim in the listing is likely bogus - the seller just misread the actual spec, which is 720x480i for NTSC and 720x576i for PAL. The last time I was capturing video, I used the VirtualDub software, which can store the raw capture in HuffYUV, however OBS can also capture interlaced video with decent compression. This capture device seems to be labeled as “BR116” based on photos in reviews, which can help identifying the chipset. BR116 is sold by Conrad and its manual by them mentions “STK1160” in a screenshot, so this Amazon one most likely also uses the STK1160 chip, which was one of the worst ones in this timebase stability test (which means it has no TBC). However, it’s alright if your VCR is a late model that already does TBC internally.

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[ - ]

1 point

2 months ago

It seems to be an EasyCAP clone, there are several devices in this form factor with different chipsets.

Good to know! That link has a lot of good information.

This capture device seems to be labeled as “BR116” based on photos in reviews, which can help identifying the chipset. BR116 is sold by Conrad and its manual by them mentions “STK1160” in a screenshot, so this Amazon one most likely also uses the STK1160 chip, which was one of the worst ones in this timebase stability test (which means it has no TBC). However, it’s alright if your VCR is a late model that already does TBC internally.

Noted! I will keep this in mind.

I came across this video about digitizing VHS tapes [1]. It talks about hardware to use, and hardware to avoid [1.6]. One of the examples that it gives for hardware to avoid seems to be a clone of the device that I was looking at on Amazon [1.2]. The rationale for why it should be avoided was that it doesn’t pass both fields of the interlaced video through independently [1.1]. Though, you have mentioned that it’s fine to capture the video interlaced, so perhaps this isn’t a big deal-breaker. The capture cards that the video recommends are:

IO-Data GV-USB2 [1.3]
StarTech.com SVID2USB232 [1.4]
Dazzle DVC-100 v1.1 [1.5]

References

“How to convert VHS videotape to 60p digital video”. The Oldskool PC. YouTube. Published: 2023-02-07. Accessed: 2024-09-14T21:09Z. https://www.youtube.com/watch?v=tk-n7IlrXI4.
1. T00:03:56
2. T00:04:08
3. T00:04:38
4. T00:04:59
5. T00:05:19
6. T00:03:50

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ChaoticNeutralCzech@feddit.org

[ - ]

2 points

2 months ago

So, uh… The EasyCAP device passes both fields into your PC but the video says that the driver does not interpret them correctly and uses probably the most common, incorrect deinterlacing method (see earlier comment with the method list). It is technically possible to reinterlace the video but I haven’t needed to do that, and you should do so before any lossy encoding to a file. I assume the community-written Linux driver has no such issue.

The tutorial is mostly correct for people who want to create YouTube uploads with just one program (for YouTube, progressive video is required and the 480p stream cannot be 60 fps and has a terrible bitrate (and 576p for PAL is not available AT ALL so 1080p60 makes sense) but I strongly recommend not deinterlacing nor scaling in OBS, you can do that later. Record 480i (interlaced) files at very high bitrate and perform the deinterlacing in post.

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[ - ]

1 point

2 months ago

So, I bought an EasyCap device and ran some tests. I encountered a few things that I don’t quite understand, and I would really appreciate your input!

I used a test VHS tape that I purchased at a thrift store (I’m not 100% sure if it’s NTSC or PAL, but I’m decently confident that it’s NTSC) (I’m also not sure what its aspect ratio is — I think it’s either 1.33:1 or 4:3). I’m playing the tape in a PV-D4745S-K VCR. I have the composite out of the VCR going into the aforementioned capture device which is connected to a computer running Arch Linux.

First, I used the following ffmpeg capture settings:

ffmpeg -i /dev/video2 out.mkv

After capturing a short snippet of the test tape, I probed its metadata with ffprobe -i out.mkv, and saw that it was strangely in 25FPS, and 720x576 (which caused the video to be stretched vertically slightly), which is PAL. So, somehow the NTSC VHS being played in an NTSC VCR was being converted to PAL. In addition to that, the colors in the video were very overexposed. I tried a bunch of different manual settings like specifying interlacing with -vf "interlace", -standard ntsc, -vf scale=720:480, -vf fps=29.97, -standard NTSC, and none of them solved the issue. I then came across this answer on StackOverflow which stated that capture cards themselves have settings for the video feed, and ffmpeg can modify them with the -show_video_device_dialog true option. From the ffmpeg documentation:

show_video_device_dialog

If set to true, before capture starts, popup a display dialog to the end user, allowing them to change video filter properties and configurations manually. Note that for crossbar devices, adjusting values in this dialog may be needed at times to toggle between PAL (25 fps) and NTSC (29.97) input frame rates, sizes, interlacing, etc. Changing these values can enable different scan rates/frame rates and avoiding green bars at the bottom, flickering scan lines, etc. Note that with some devices, changing these properties can also affect future invocations (sets new defaults) until system reboot occurs.

Unfortunately, when trying this option, an error popped up saying that the option was unrecognized. After some digging, and prompting ChatGPT, I found that apparently that option is Windows only as it relies on Windows’ “DirectShow system”. The way to modify it in Linux is to use the Video4Linux2 framework, which is controlled with v4l2-ctl. So, I ran the following:

v4l2-ctl --device=/dev/video2 --list-formats-ext

which showed the following entry:

...
[0]: 'YUYV' (YUYV 4:2:2)
    size: Discrete 720x480
...
        Interval: Discrete 0.033s (30.000 fps)
...

So it is able to output NTSC — ie 720x480 at 29.97fps (I guess it rounds up the fps for whatever reason). So I then tried

ffmpeg -f v4l2 -video_size 720x480 -i /dev/video2 out.mkv

and it was able to output the video at 720x480 29.97 fps as desired, and the colors were no longer super overexposed. Using the -vf "interlace" flag, I do seem to also be able to capture interlaced video, so it also doesn’t force progressive which is nice.

I thought that the capture card would be able to just autodetect what the input resolution was to allow ffmpeg to record at that, or at the very least, I would expect that specifying NTSC in ffmpeg would force the standard, but neither of those worked and I’m not sure why. There’s also still an ongoing issue of the video being zoomed in/cropped slightly (I verified this by comparing against online sources of the same video (some were a VHS rip, others from non-VHS sources)). I tested the VCR’s output on a regular TV, but unfortunately the TV forced 4:3 and cropped it even more, so I wasn’t able to make a perfect comparison, though that was only additional horizontal cropping — the vertical cropping from before was still present. To be able to verify that, I’ll have to pick up another test VHS tape to see if perhaps the test VHS tape that I currently have was just recorded in a cropped format.

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