On Mon, Oct 22, 2018 at 09:32:57 +0200, Ben wrote: > I wanted to encode (and resize) an existing MP4 file into a new MP4 video and > a width of 1680 * ... and an aspect ratio of 16:9 > The used codec is H.264 > > Since the calculated height therefore is (1680/16)*9=945 I entered this for > the ffmpeg command and got an error: > > "height not divisible by 2" > Hmm, can this really be?
Yes, certain operations and codecs have such requirements. For example the very common H.264 with yuv420p colorspace. > What is the recommended height otherwise? Some codecs even encode more efficiently when the resolution is divisible by 4, 8 or possibly even 16. In your case, just choose a height divisible by two. > Is there no auto-adjustment in ffmpeg? No, but if you use the scale filter (or others using the same size syntax), you can let ffmpeg do the math for you: Resize while keeping input aspect ratio, but divisible by 2: $ ffmpeg [...] -vf scale=1680:-2 [...] If you want to be explicit about 16:9 (and let ffmpeg calculate 16/9): $ ffmpeg [...] -vf "scale=trunc(1680/2)*2:trunc(1680*9/16/2)*2" There are some other nice suggestions in this StackOverflow topic: https://stackoverflow.com/q/20847674/3974309 Cheers, Moritz _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
