How to make a 25 FPS SMPTE DCP and a 24 FPS INTEROP DCP from a 25 FPS Quicktime file in Easydcp 2.0 (and convert sound FPS)


Converting Sound FPS

You can use Wave agent to convert between different frame rates with the changing sample rate/resampling trick. Example: 23.98 fps sound files to 24 fps. Use 48048 as the sample rate in Wave Agent.

Sample rates conversions:
23,976 (NTSC with 3:2 pulldown) -> 24 = 48048
24 > 23,98 = 47952
25 -> 24 (4800×24/25) = 46080
24 -> 25 (4800×25/24) = 50000

How to change sound frame rate with Sound Devices Wave Agent and iZotope RX

Wave Agent changes the sample rate in the metadata of the sound files similar to what Cinema Tools conform did on Quicktime files. iZotope RX does batch processing, SRC resampling, and MBIT+ dithering. This method keeps phase sync, but the pitch will be lower.

Make a copy of the sound files.
-Drag the sound files to Wave Agent.
-In Wave Agent, mark all files, choose a new sample rate, and press enter, then save.

in iZotope RX
-Open Batch processing,
-Drag the modified sound files to the Input files window
-Choose apply resample
-Choose view
-Choose the 48 kHz DVD preset and post limiter
-Choose record
-Choose 24 bit and MBIT dither

Alternatively, you can use Timefactory 2.5 to change the frame rate on soundtracks.
-You keep phase sync
-The pitch shift algorithm will try to keep the same pitch as the original, but this may introduce audible artifacts.

-Drag sound files to Timefactory
-Join sound files (if necessary).
-Use Expert settings – IN FPS and OUT FPS. Example 25 > 24 (104,166). 25 -> 23.976 PAL (104.27094)
-Choose algorithm. Example: Dirac.
-Choose process.

How to make a 25 FPS SMPTE DCP and a 24 FPS INTEROP DCP from a 25 FPS Quicktime file

With Easydcp 2.0, you can make DCPs from Quicktime files like 1920×1080 ProRes 422 HQ. The Apple Prores codec and the JPEG2000 codec used in DCPs are both visually lossless codecs. If you do not have a fast RAID setup, this can speed up the process of making DCPs compared to making them from a TIFF or DPX image sequence. But if the source files need deinterlacing and scaling, you still need to deinterlace/scale the source to either 1998×1080, 1920×1080, or 2048×858. To make a ProRes 422 Quicktime, you can use Adobe Premiere Pro or Final Cut X.  To encode Prores 422 on windows, you can use Adobe Premiere or Media Encoder

When you make a 25 FPS SMPTE DCP from a Quicktime file, Easydcp stores the audio files in a directory of your choice, and you can convert these files later to 24 FPS and use them to make a 24 FPS INTEROP DCP that will play on older hardware. Using Adobe Audition to extract sound files from Quicktime files is also possible.

If you copy the sound files from the directory to a new directory and open them with Wave Agent, you can slow the sound down to 46080 Hz (25 -> 24 FPS).  You can use iZotope RX  or similar software to resample 46080 to 48000 and then save as 24 bit.

These files can then be used together with the 25 fps Quicktime or MXF in a 24 FPS INTEROP Easydcp project to make a 24 FPS INTEROP DCP. With a 24 FPS INTEROP Easydcp project, you can also add Interop subtitles. You can also add a 25 FPS picture MXF file with the subtitles burnt in.

3 thoughts on “How to make a 25 FPS SMPTE DCP and a 24 FPS INTEROP DCP from a 25 FPS Quicktime file in Easydcp 2.0 (and convert sound FPS)”

  1. Pingback: How to output (EASY)DCP friendly DPX sequences from After Effects | Knut Erik Evensen - KESE

  2. Then I can import a 25fps movie in a 24fps esydcp project, with the correct 24fps audio and make a 24fps DCP from the 25fps file?
    I can even use the 25fps mxf from an already encoded dcp to make a new 24fps DCP without recompression?

  3. Knut Erik Evensen

    Yes. You can use a 25 fps video file in a 24 fps project if you have used the resample method to change the length of the audio.
    Yes. You can use a 25 FPS DCP video MXF file in 24 FPS DCP project.

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