On Sat, 2006-10-07 at 22:43 -0500, Matt Pfingsten wrote: > A while back I was having issues importing QuickTime DV files that had > been captured on a Mac with Final Cut Pro. I learned that, apparently, > in spite of the fact that Cinelerra both claimed they were compressed > with the DV codec and were quicktime files, someohow the FCP quicktime > was different.
Alas, there are often many possible ways to follow a specification. If one of the implementations (say, Cinelerra) assumes only one particular way, it will only be fully interoperable with other implementations that make the same assumption. Which is bad. > Here is a comparison between three different clips: > > 1) A file called fhmp_footage.mov. This first file is some footage > captured in Final Cut Pro. > -In Cinelerra, playback is choppy and only every fourth or fifth frame > is displayed. > -In MPlayer it plays fine. "mplayer -identify fhmp_footage.mov" yields > this: (relevant portions only): ID_VIDEO_FORMAT=dvc, and later > ID_VIDEO_CODEC=qdv > -FFMpeg cannot play it, complaining "could not open codecs." > > 2) A file called 16A-1.mov. This is a clip I shot two weeks ago and > captured using dvgrab. > -Cinelerra plays it back fine. No issues. > -In MPlayer it plays fine. "mplayer -identify 16A-1.mov" yields this: > (relevant portions only): ID_VIDEO_FORMAT=dvc, and later > ID_VIDEO_CODEC=qdv > -FFMpeg can play it. "ffmpeg -i 16A-1.mov" identifies the video as > dvvideo. FFPlay plays it fine. > > 3) A file called titles_end.mov. This clip was created in Cinelerra > from a bunch of PNG files. It is a one minute title sequence. > -Cinelerra can play it back fine. No issues. > -MPlayer/MEncoder have no problems. "mplayer -identify titles_end.mov" > yields this: (relevant portions only): ID_VIDEO_FORMAT=dvc, and later > ID_VIDEO_CODEC=qdv > -FFMpeg can't play it, complaining "could not open codecs." > > Cinelerra identifies all three as DV Codec compressed Quicktimes. These are interoperability problems, where it is evident that the files are easily decodeable with Free Software. Hence, they are bugs in Cinelerra. Now it is important that the developers get a chance to reproduce the bugs you experienced. They need small sample files that demonstrate the problem. > It should also be noted that Kino 0.9.1 can't open any of these files > without complaining that the file isn't a DV file and wanting to > import it via MEncoder. This problem will hopefully pass. But I think it should be bugged as a regression in Kino. -- Herman Robak _______________________________________________ Cinelerra mailing list [email protected] https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
