I want to take footage from modern video cameras (1080p @ 60fps MPEG-4 AVC + AAC/LPCM audio) and convert them, preferably with
ffmpeg, to a legacy interlaced QuickTime DV or HDV file that can be used in Final Cut Pro 6 on a PowerPC Mac, such that FCP6 will treat it identically to captured [H]DV footage from a real [H]DV camera. It shouldn't just be a conversion to a DV codec, it should work in FCP6 as if it's real DV footage captured in FCP6's capture facility.
I'll be transcoding on a Windows system, not on a Mac with Compressor. I have plenty of power on the PC side to transcode the footage. If there is a way to transcode 1080p60 AVC footage to a usable format on a G4/G5 Mac, I'd be interested in insight into the process, but that probably won't be practical.
Alternatively, if that is not reasonably possible, I'd like to downscale and convert to a ProRes format that's supported by FCP6 and that won't bog down a high-end G4 or low-end G5 tower. I have played with ProRes conversions through
ffmpeg before, but my converted files seemed "too heavy" for the iMac G5 I tried them on. [H]DV format is strongly preferable. Shooting 1080p30 or 720p30 is an option, especially if converting to ProRes instead of DV.
This question is often asked in reverse ("convert DV to MP4" etc.) but that's not the case here. To preempt questions about why I want to do this: I'm working on a video about the days of FCP6 and my only DV camcorder's main motor fried, so I need to substitute in a camcorder that records MP4/MOV files with AVC video and AAC or LPCM audio.