Hi Andrew, Thanks!
Andrew Church wrote: >>> I'd like to create thumbnails every ten seconds from a video. This works >>> for a continuous series: >>> >>> transcode -o thumb -y ppm,null -y im -F png -x ffmpeg,null -i >>> dx50.avi -c 0:0:0-0:0:01 >>> >>> Is there a way to set -c so that I get one frame every ten seconds? >>> > > Try --frame_interval 300 (assuming 30fps video). > This works and is obviously a lot simpler than the long list of -c values I'm using right now, but the speed is actually slower -- around 173 fps vs 205 fps when I use the -c flag. It's also not as precise -- I get 418 images per hour instead of 360 as I should -- and do with the -c flag. > >> Surprisingly, this exports the first ten seconds instead of the first >> and 300th frames: >> >> transcode -o thumb -y im -F png -x ffmpeg,null -i dx50.avi -c 0,300 >> > > Technically, that's invalid syntax (-c accepts ranges, not single frame > numbers); CVS HEAD will properly report an error. Would it be useful to > allow single frames to be specified with -c? > Yes, that would be very useful. It would also be extremely useful to be able to specify a regular interval between images, for instance in the format x-y::z, where x is the start, y the end, and z the interval between the exported images, each given either in frames or in hh:mm:ss. This sort of thing is useful for creating searchable databases for video material. David
