Avid outputs at 59.94 playing back at 2x speed?

[Ben Pluimer]

(Cross posting this from the workflow section in case this gets more eyeballs on it)

We're doing camera tests for a network show, and post has requested our 4kHD 29.97 files to be transcoded to 720p 59.94 Dnxhd 145. I don't have Avid on my machine so I can't see exactly what's going on, but they tell me the transcoded files are playing back at what looks like 200%. Is there a different process I should use (ie output from RedCine at 29.97, and then convert to 59.94?

Link to the file in question: http://dl.dropbox.com/u/2302114/A007_C001V019FCC0001.mxf

Can anyone offer me some transcode advice or solutions to this? Thanks.

 

[Eric J Robbins]

If possible, always shoot in the deliverable timecode. What is happening here is the output sees the first 30 frames you shot (which is a second of playback at 29.97) and is assuming they are the first 30 frames of a 60-frame second. That's why the motion is fast. Is there any reason why you were shooting at a different frame rate than they were expecting for delivery? Is it possible for them to edit off of 29.97?

 

[Eric J Robbins]

Also, which version of Avid are you using? MC 5.x and beyond support mixed timecode sequences, so they should be able to bring it into a 720p 59.94 project as a 29.97 clip.

 

[Ben Pluimer]

This is all coming from the network post department, so I'm not sure which version they are using. We shot and delivered a 29.97 file and that worked perfectly, but because of broadcast standards they have asked for a 59.94 test. The scarlet does not shoot 59.94 at 4kHD, hence the needed conversion. My suggestion might be to edit in 29.97 and output at 59.94, but I want to accommodate them as best as I can for now.

 

[Peter Majtan]

I have had this issue with NHK here in Japan (after shooting a show on my Scarlet when the HD-CAM decided to call it quits 3 hrs away from Tokyo). Make sure to confirm that the 59.94 is or isn't interlaced. NHK needed all shots (shot at 29.97 progressive) to be transcoded to DVCPRO-HD at 59.94 1080i (interlaced)...

If it is progressive - you might have a problem, as 30P (29.97) does not scale to 60P (59.94) without strobing (each frame is duplicated). You will need to use post software (FCP, Compressor, or really anything else) to re-time the 30P to 60P (slow down to 50%). For higher quality results you will need to use TWIXTER or something like the Kronos on Nuke - which is time-consuming...

Peter

 

[Ben Pluimer]

I have had this issue with NHK here in Japan (after shooting a show on my Scarlet when the HD-CAM decided to call it quits 3 hrs away from Tokyo). Make sure to confirm that the 59.94 is or isn't interlaced. NHK needed all shots (shot at 29.97 progressive) to be transcoded to DVCPRO-HD at 59.94 1080i (interlaced)...

If it is progressive - you might have a problem, as 30P (29.97) does not scale to 60P (59.94) without strobing (each frame is duplicated). You will need to use post software (FCP, Compressor, or really anything else) to re-time the 30P to 60P (slow down to 50%). For higher quality results you will need to use TWIXTER or something like the Kronos on Nuke - which is time-consuming...

Peter

So would the solution be to shoot and edit at 29.97, and then convert to 59.94 for output?

 

[Peter Majtan]

So would the solution be to shoot and edit at 29.97, and then convert to 59.94 for output?

That's what I did for NHK and they were happy...