How do I convert 1080p 29.97fps to 23.976fps with Avisynth?

[MrBiggles]

Does anyone have a script please?

I was wondering as well. Are all TV series these days on Bluray in 23.976fps?
I always thought that films are 23.976fps but TV series are shot on video and are 29.97fps interlaced.
So I was just wondering what framerate TV series on Bluray are in and are they progressive or interlaced?
Is there any place I can find that out without randomly trying different conversions?

[poisondeathray]

Yes, American TV series (such as dramas, theatrical series) are all 23.976 , and the BD version is usually progressive 23.976 already

If you have a telecined version (it would be rare for BD, because native progressive is supported) , you need to IVTC to get the original progressive frames back

Most likely it would be something like

TFM()
TDecimate()



But a non theatrical American series might be interlaced 29.97 frames per second (59.94 fields / second) . eg. a sports series

A series from elsewhere like BBC, would be 25p content but encoded interlaced

[MrBiggles]

OK thanks. Reason I ask is that I'm trying to capture some Amazon prime exclusive videos that aren't on DVD or Bluray. They are standup comedies. So I wasn't sure what framerate they originally were before they were put on Amazon Prime.

To test it, I used the Elgato Game Capture HD to record my PC. I tested recording Banshee Season 1 which is an action-drama series. I used the Game Capture HD which only records in 1080p at a max of 29.97fps. Framerate looked unsmooth. I also tried converting that to 23.976fps. Looked even worse.
So I assume that was NOT shot on film. If not then must it have been shot on video at 29.97fps interlaced?
I say all the above because I used the Game Capture HD60 which records in 1080p 59.94fps and the video looked much smoother. Any thoughts?

[poisondeathray]

It could have been recorded 59.94p (progressive) too . I guess what matters more, now, is what you actually have. Any number of (bad) things might have happened between point A and point B. If you can't figure it out , you should post a sample clip with steady movement

[johnmeyer]

I haven't found anything that captures streaming at any sort of consistent frame rate. Most streaming services are provided at variable frame rate, in order to keep up with changing bandwidth conditions. If you put your captured video into an editing program and then "walk" through it frame-by-frame, you'll probably see a lot of duplicated and dropped frames. Also most 29.97 interlaced content is usually degraded to 29.97 progressive.

In general, while video streaming can look pretty darn good, it is generally not a great source for building your own library of material

[MrBiggles]

On closer inspection, playing my Elgato 29.97fps or 59.94fps video on my TV there's no dropped frames but the framerate isn't as smooth as the source. I suppose you could compare it to converting an interlaced video NOT shot on film to 29.97 fps progressive instead of double framerate. That's what my recording looks like.

Also tried Replay Video Capture but it drops frames.

I have a 50 Mbps download speed so I believe I'm getting a consistent FPS in Amazon so I don't see why a progam couldn't record in that framerate.

[jagabo]

It's easy to determine of your 30p cap was originally 24p. Step through the video frame by frame in an editor. If you find a duplicate frame every 5th frame the source was 24p. Use TFM() in AviSynth to selectively remove the duplicate frames.

In my experience, most sites that stream movies and TV shows do so at 30p. And the video should be decimated to 24p.

[MrBiggles]

So the only thing I need in my script is to change the framerate from 1080p 29.97fps to 23.976fps is the below. Is that correct?

TFM()

[jagabo]

So the only thing I need in my script is to change the framerate from 1080p 29.97fps to 23.976fps is the below. Is that correct?

TFM()

Yes. But it's only correct for the situation I described.

[poisondeathray]

jagabo probably meant TDecimate() to remove the duplicate frames for a 29.97 web capture

[jagabo]

Jeez. Yes. TDecimate(), not TFM().

[MrBiggles]

Yes you are correct only the following worked:

TDecimate()

I've attached a 720p 29.97fps source Elgato PS3 recording from Amazon Prime so you can see for yourself. It's a few seconds long and shows you a panning shot so you can see how smooth it is. So it seems that the best way to record on demand is on a PS3 as the end results (after decimating it if needed) matches the framerate and smoothness of the stream exactly and of course you can record in the bitrate and resolution you want. It doesn't play back very smoothly on your monitor but play it on a media player or Bluray player connected to your TV and it plays back smoothly.

I've tried recording my own PC using the Elgato and the framerate wasn't smooth even though my CPU usage was low. Tried using PlayLater to record from the PC and got glitches.

Was wondering, I noticed that 720p on the PS3 gives an obviously better quality than 1080p. Why do you think that is? Do you think 720p is getting the same bitrate that 1080p would and that's why it looks better? Or is Amazon Prime only outputting 720p and and PS3 is upscaling to 1080p which is why it looks so bad as the PS3 upscaler is rubbish.

On what footage do you use TFM() and TDecimate()?. Could you possibly please explain what TFM() does. Instructions says "TFM is a field matching filter that recovers the original progressive frames from a telecined stream." I understand that part but what is telecined video, is it the same thing as interlaced video?

On what sources do you get telecined video?

[jagabo]

TFM().TDecimate() is for telecined film. Ie, capturing 1080i, not 1080p. TFM() matches fields to produce 30p. TDecimate() removes the duplicate frames to give 24p.

Amazon Prime is probably sending 720p. If you upscale to 1080p you are just making more data to compress. If you compress 1080p with the same bitrate as 720p the latter will have fewer artifacts.

[manono]

Ahhh... Banshee. I just finished enjoying Season 1 on Amazon Instant Video. As you can see when stepping through the sample frame-by-frame, every fifth frame is a duplicate. A perfect candidate for TDecimate().