I record old Noir movies, streamed over the Net. (For personal use, to watch later on the Flat Screen TV.) tcm.com, for example.
I use OBS Studio to record/capture the movie playing full screen on my monitor.
My monitor is capable of a 75 Hz Refresh Rate. Which is what I have it set to for daily use to help relieve eye strain.
But for recording movies, I have found that I get better results capturing movies when I lower my monitor's Refresh Rate to 60 Hz. When I capture movies with my Monitor Refresh at 75 Hz, I get stuttering in high motion sections of a capture. (E.g., a waterfall scene.) A close examination, frame by frame, shows many duplicate frames - as much as 3 for 1. (Indicating that there some kind of telecine routine going on between the streaming end and my monitor?)
My question for the forum is: What is the best Monitor Refresh Rate for capturing old movies? And similarly, what is the best frame rate for OBS? And maybe, even, what is the best browser to capture from? Or?
As it goes to the second question, one problem that I've seen is lost frames.
I made a short video which shows the problem. (Although my video used different frame rates than I talk about below, so a bit of apples vs oranges here. )
Perhaps I'm confused about how all this works. (And/or there is more that's going on during capturing that meets the eye.)
We know that old films were recorded at 24 fps.
I'm assuming that these old movies, when streamed over the Net, are being played from a Blu-Ray file. (It's certain that these movies are digitized. Else a Projectionist would have to mount a film when you call it up, project it onto a screen at his end, and transmit the result, like in the Old Days of TV.)
I read that Blu-Ray has a frame rate of 24 fps. I am guessing that the way that Blu-Rays are made is that a special machine steps through a (film) movie frame by frame, scans a frame, and moves on to the next. And since these are 24 fps film movies, I thought that I should set OBS to 24 fps also to capture every frame.
But when I set OBS to capture at 24 fps, I would miss frames occasionally, as in my sample video, above.
So then I tried 48 fps, thinking that I was missing some frames due to syncing issues. I thought that oversampling would solve the missing frame problem.
But it didn't.
Well, maybe it did. But it also put duplicate frames in the capture. Which gives a stuttering effect in fast moving scenes. (I used to have a test video to show that effect. Don't have it now.)
It seems that streaming movies are not always exactly in sync? (Dropped packets? Changing delays in packet routes?) Or that there are some other factors in play?
I'll tell you what I've found (via experimentation) works best for me here, although I can't fully explain why. I set my Monitor's Refresh Rate to 60 Hz. I use Waterfox browser. I check to make sure my download speed from tcm is 45 Mbps. (If not, I refresh the web page.) I set OBS to 30 fps. I also set OBS to use 4 Keyframes and Max B-frames of 4. CBR with a Bitrate of 9000 Kbps. No Look-ahead and No Psycho Visual Tuning. I still get an occasional duplicate frame in fast moving scenes. But not to the point that I notice any glitching in a panning view of a fast moving waterfall. (E.g. the waterfall scene from The African Queen.)
And you all say ... ?
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Last edited by pmikep; 15th May 2021 at 12:02.
Ironically, I initially posted my Question in the Capture forum. And then I saw the Streaming forum and asked the Mega Moderator to move it here.
I made the remark in jest anyway, sorry its my weird sense of humour. Enough people use OBS my self included (daily) so someone may be able to assist / advise.
Ever considered grabbing from the tcm source ? then this really would be the place to ask. (Unless its sub based).
I don't think it's a good idea to try to capture that stream with OBS..
Whatever frame rate/source/monitor frequency you may choose.. you'll end up with messy results, since OBS can miss some frames from time to time (being a real-time capture application having as a source a streaming video on the web - they'll never be 100% in sync, whatever you do ), so at 99,999 % you will end up having some dropped/duplicated frames on your recording at some points.
PS: monitor refresh has not relevance at all.. since the real issue is that you're trying to match things that are impossible to be (perfectly) matched (for the reason above).
Last edited by krykmoon; 14th May 2021 at 14:54. Reason: Make the explanation more clear
You mean like a "youtube downloader" app for tcm?
No, I've never thought of trying that.
I might have looked into some kind of video grabber years ago but I saw a whole bunch of sub-streams (?) coming in. And constantly changing.
And I suspect that tcm does everything it can to thwart video downloaders.
But you are all correct - trying to download the stream directly would be the best technique.
So then, in doing a search of the forum for how to "download" movies from tcm, I find that someone asked before here, and was told that it's a violation of forum rules to ask about such things.
So I guess I'm stuck using OBS Studio as a workaround.
I was using OBS myself and put up with all the added duplicate frames and funky reencodes. Now I can capture the original broadcast. And if you're using a streaming service for the TCM caps, you might be able to use a very good capture program, one such as DVDFab DRM Downloader.
[ss]vegeta PM'd me, saying, "Give me link to tcm, user/pass and I'll try to download, then show you how."
Hmmm ... maybe I should send my Credit Card info too?
Keep on recording with OBS, proper way to get and watch movies
Also, please do throw money at these dvdfab blabla that sometimes work sometimes not and keep on waiting for updates.
Also also buy capture cards and wait for them to arrive and try to set them up to work properly.
Last edited by [ss]vegeta; 18th May 2021 at 11:22.