View Full Version : Replace audio Cineform track in FCP - unnecessary encode


Anmol Mishra
May 24th, 2011, 12:05 AM
Hi! I am using pluraleyes to replace an audio track from the camera with one recorded off camera. I have the camera file aligned with the off-camera audio.

Now I proceed to delete the audio from the camera file.

At this time when I export, (keeping the same settings) FCP should just re-encode the audio. This should not be more than a few minutes.

I get 7 minutes on a quad core for a 2 min Cineform file. This leads me to believe that FCP is re-encoding the original file.

Is there a way to prevent this ? To force a "Smart Encode" where only the audio is encoded ?

Craig Davidson
May 24th, 2011, 10:50 AM
When you export (Export QuickTime...) make sure that the option to "Recompress All Frames" is not checked.

Anmol Mishra
May 24th, 2011, 11:12 PM
Hi Craig. That option is not checked. I have exported qt references before and they work well with ProRes.
Could I suggest that you try this on a Mac ? Its easy to see what would or would not work.

A qt reference would be faster than realtime - so a 1 min. clip would take less than a min. If you are taking 20 min to export a qt reference, clearly FCP is recompressing the CF file.

Craig Davidson
May 26th, 2011, 10:33 PM
I tried that on my laptop (Mac) and exported a timeline almost 3 minutes long in 5 seconds.

Anmol Mishra
May 27th, 2011, 04:45 AM
Interesting, is there anything special in your Sequence or A/V settings ?

I only have the recommended settings in Sequence, CF as the render codec, everything else the same.

Does it matter if there are lots of cuts in the timeline for a CF qt reference ?

Craig Davidson
May 27th, 2011, 02:54 PM
It should not matter if there are a number of clips in the sequence. I tried a longer 'movie' with 4 clips and it still only took about 5 seconds. I added a title over some clips, and that did render.
The sequence matches the source clip. Start with an empty project, add a clip and let FCP match the sequence settings to the clip.

Anmol Mishra
May 28th, 2011, 01:40 AM
I did a few experiments today. Turns out that when I created my projects, FCP asked me to match the sequence settings. I said No.

Now I have an hour of edited footage that refuses to conform to the sequence settings.

Hence I cannot make a qt reference, and everything is re-rendered. If I start a new project nd bring in the files fresh from the hdd, it renders fine.

I tried using the manual conform - that does not work either.

Any suggestions ?