Thanks enormously to everyone who responded to my request and participated in this video metadata experiment, which was a success: we've gathered a ton of useful data in just 24 hours. I never cease to be amazed by the cooperative spirit of the open source community.
See http://trac.yorba.org/wiki/VideoMetadata for a list of all the data we've gathered. The immediate conclusions are as follows: - Almost every camera tested uses either the QuickTime/MP4 container format (extension .MOV or .MP4) or the AVI container format. - MOV/MP4 containers usually store video in MPEG-4 or H.264 format. AVI containers usually store Motion JPEG. - qtdump (and, hence, libquicktime) can usually read the correct time when a MOV/MP4 video was filmed. There appear to be time zone issues in some cases. - qtdump/libquicktime can never read the correct time when an AVI video was filmed (even though libquicktime has some support for AVI files). For these videos qtdump reports the current time. Yesterday Jim enhanced the Shotwell trunk so that it can read a MOV/MP4 video's time using libquicktime (which is a new Shotwell dependency). That will be a nice feature, though we should continue to investigate the time zone issues I mentioned above. Fortunately we've found that AVI videos do actually have an embedded time indicating when they are recorded. Unfortunately, the only tool we've found that can read an AVI video's time is exiftool, which is written in Perl and so we can't easily embed it in Shotwell. In theory, Shotwell could spawn off an command-line instance of exiftool when it needs to determine an AVI video's time, but I'm loathe to do that. Perhaps we can study what exiftool does and imitate it somehow. We'll continue to investigate. Of course, it would be great if some higher-level framework (either ffmpeg or GStreamer) could report video metadata so that we wouldn't have to deal with MOV/MP4 and AVI videos separately. We have looked at these frameworks a bit and haven't found any way to get the video metadata we need from them, however. Thanks again to everyone who participated in this video experiment! adam On Thu, Nov 11, 2010 at 10:24 AM, Adam Dingle <[email protected]> wrote: > As most of you know, Shotwell 0.8 will support videos. We'd like Shotwell > to read date/time metadata from video files, just as it does for photo > files: this will let it place imported videos into events. Unfortunately, > our first experiments in reading video metadata have yielded inaccurate > times for some cameras. We'd now like to gather more information about > whether we can get a reliable date and time from video files recorded by > most cameras that people are using today. > > If you have a camera which can record video and a few minutes to spare > performing a simple experiment, you can help: see > http://trac.yorba.org/wiki/VideoMetadata . Thanks! > > adam > > _______________________________________________ Shotwell mailing list [email protected] http://lists.yorba.org/cgi-bin/mailman/listinfo/shotwell
