I have been working on a mountainbike documentary which is about 65 minutes long. Everything was shot in PAL HDV format. The problem came when i went to figure out distribution of the film. It turns out that NTSC would be the best format for international distribution since most Pal players will play NTSC disks.
The problem was how to best convert from PAL to NTSC. There are two methods I have generally come across. One is to use some kind of format conversion software like Apple Compressor which can blend the frames in different ways to get the desired frame rate. The other, which i will be looking into here is to reconform the footage to 23.98FPS. The benefit to this method is that you are not recompressing the frames or reducing the quality. The down side is that the end footage plays back around 4% slower
So lets get started…
Firstly select your sequence in FCP and export it using the ‘Export Quicktime Movie’ option. I selected the ‘Make Movie Self Contained’ check box so that all the footage will be contained in the exported file and not just references. You also have the chance here to include any makers you added in FCP.
Once the movie has been exported I made a duplicate using the Finder so that I would have the original PAL master as an archive file.
Open Cinema Tools and then choose file/open clip. Open up the File you just duplicated, then select conform to 23.98fps and you’re done!
One problem with conforming the footage is that the audio pitch will be lower slightly. Some people do not mind this, others do. To fix this you need to:
Open up the original PAL master in Quicktime Pro. Export 48khz aiff audio. Open up the exported file in Soundtrack Pro and then time stretch. There are a number of different options here but I use sample units to stretch. Pal audio has 1920 48khz audio samples per frame and 23.98 NTSC has 2002, so I simply divide the number of audio samples as shown in the time stretch dialogue box by 1920 and then multiply by 2002, then enter that number into the samples field.
Export the audio file as 48khz aiff and include ‘stretched’ in the file name so you don’t get confused. Now run the conformed video and stretched audio through Compressor and you will have your NTSC DVD files ready to import into DVD Studio Pro.
