lecoyote418 (u/lecoyote418)

lecoyote418 commented on Why 23.976 and not 24 FPS? (2016) cinematography.com/index.... · Posted by u/mfiguiere

thrdbndndn · 3 years ago

> Video on demand, which supports any framerates, is now the main distribution channel

But all the major VOD services, be it Disney+, Netflix, Hulu,... still mainly use 23.976 or 29.97 fps for their video distributions.

I don't know what your production company mainly works on, but these NTSC frame rates ares still the norm across the whole cinematic industry, and it's not going anywhere. It's not limited to documentaries at all.

The YouTubers etc. do use 30/60 fps more often OTOH.

lecoyote418 · 3 years ago

Good question. Last time I've submitted to Netflix, it was 24, but it goes through a third party "packaging" company before going to Netflix.

So some of them might reconvert to 23.976 even when we submit 24 fps masters as per the contractual agreement. Maybe you are right. I will check.

Low budget web series shot at 23.976 even get delivered and played back at 29.97i on some local platforms here in Canada (Crave, Noovo, tout.tv), so anything's possible nowadays.

On the other end, Blurays can be encoded at both 23 and 24, and Vimeo, Youtube, etc all support 24fps. So 24 fps exists, not just on DCPs.

By the way, the loss of quality from going to/from 23.976 and 24 is not much. I've never heard any artifacts from that kind of conversion. But since cinema theatres are most likely to have a better sound system that a home system, I think it makes more sense to have the unconverted mix playing in the cinema and not vice versa.

lecoyote418 commented on Why 23.976 and not 24 FPS? (2016) cinematography.com/index.... · Posted by u/mfiguiere

pushrax · 3 years ago

Production audio and video recorders generate or intake an SMPTE timecode signal, and stamp recordings with this timecode.

This timecode format is a timestamp with seconds resolution plus a frame count within each second. To properly sync, all the timecode generators must use the same framerate. In other words, the audio recorder’s timecode framerate needs to match the camera.

lecoyote418 · 3 years ago

Yes, sound needs to be recorded with proper metadata, otherwise the sync process with the image is going to be pretty tedious. We could just record with a "dumb" audio recorder that doesn't write timecode and fps metadata and it would sync up by hand to any camera FPS (23.976, 24, 25, 29.97, etc). It's not just practical for any professional projects.

The funny thing with timecode, which is hh:mm:ss:ff, is that the frame count is done at 24 frames, even at 23.976. So 1 frame of 23.976 is longer in actual "real time" duration than 1 frame at 24 fps. This can get confusing when going from and to 24/23.976.

There are more sophisticated workflows where the audio is recorded at 48.048 kHz (0.1% faster sample rate) called audio pull-up (or pull-down). The technique is used when shooting, for example, a TV spot, with a film camera at 24 fps. Since the 24 fps picture will be played back at 23.976 at the edit, the audio will follow the same speed down because it will itself play at 48.000 kHz instead of 48.048 kHz. I'm not sure that many productions still shoots TV spots in film, though, contrary to fiction where film is still being used sometimes.

lecoyote418 commented on Why 23.976 and not 24 FPS? (2016) cinematography.com/index.... · Posted by u/mfiguiere

garaetjjte · 3 years ago

It's not straightforward and might introduce artifacts.

lecoyote418 · 3 years ago

There are algorithms that are better than others.

For example, ffmpeg's pitch correction using "atempo" filter (WSOLA) is average and might present artifacts depending on source audio.

ZTX (was Dirac) is another algorithm that's commercial and pretty much artifact free.

Btw, sound studios responsible for the 24-25 pitch shift often have the possibility to process the pitch shift on separate dialogue, music and effects tracks, limiting even more the artifacts in the converted output.

lecoyote418 commented on Why 23.976 and not 24 FPS? (2016) cinematography.com/index.... · Posted by u/mfiguiere

lecoyote418 · 3 years ago

This post was 2016. Six years later, this is no longer true, at least here in my area (Montréal). At my work in a post-production company, we finish around 8-10 long form fiction movies a year and a bigger number of shorts, and I would say around 90% of thoses projects are now shot 24.0 fps.

All high-end cameras like the ones from Arri, RED and Sony can switch easily between 23.976 and 24.0 since many years. The sound recorders can now too, like the Sound Devices, which is the most common brand used (at least here in North America). The choice of shooting in 24.0 was already available in 2016, but not every gig would be used to shoot 24.0 so they chose 23.976 just to be safe, I guess.

Also, in 2016 television was still a major deliverable, but this has changed. Video on demand, which supports any framerates, is now the main distribution channel when a movie has finished playing on the big screen.

Documentaries are more of an exception because they are still aimed at television and also, they often use old footage which was telecine'd at 23.976 so it's easier to edit when everything's 23.976.