I Bloom
08-29-2008, 08:50 PM
I don't believe this is a specifically RED situation but I figured I'd share it since most of us are recording seperate sound with 23.98 timebase.
I discovered on a recent production that seperate audio was drifting in the timeline in FCP. It would drift about 2 frames over 2 minutes. I couldn't figure out why since the audio was recorded 48khz and we had a clap slate that was matching perfectly. (It was 23.98 footage transcoded to pro-res with RedRushes)
I discovered that if the audio files were transcoded from 24bit/48.000khz .WAV to 24bit/48.000khz .AIFF the drift problem went away. You could place the transcoded file on the same timeline and it would stay in sync just fine.
I don't know exactly why this is happening but my theory is that the the hard disk recorder that created the .wav files was placing embedded timecode into the files and that timecode may have been running at 24.000.
I'm not really an audio guy or an editor, I just thought I'd share my experience and see if anyone could shed some light.
IBloom
I discovered on a recent production that seperate audio was drifting in the timeline in FCP. It would drift about 2 frames over 2 minutes. I couldn't figure out why since the audio was recorded 48khz and we had a clap slate that was matching perfectly. (It was 23.98 footage transcoded to pro-res with RedRushes)
I discovered that if the audio files were transcoded from 24bit/48.000khz .WAV to 24bit/48.000khz .AIFF the drift problem went away. You could place the transcoded file on the same timeline and it would stay in sync just fine.
I don't know exactly why this is happening but my theory is that the the hard disk recorder that created the .wav files was placing embedded timecode into the files and that timecode may have been running at 24.000.
I'm not really an audio guy or an editor, I just thought I'd share my experience and see if anyone could shed some light.
IBloom