Using FFMPEG To Prep Video For Whipple Hill Podium
Even going to Adobe CS5 and switching OS X 10.6.x to 64-bit doesn’t really make the process of taking Quicktime video to Flash in a reasonable timeframe. So, enter FFMPEG command-line tools. I have been playing with many different settings to get the performance and quality at an optimal state for playback in the Whipple Hill Podium Media Gallery.
Whipple Hill recommended (as of 9/13/10) video settings for the gallery should be
- Audio sample rate: 22050
- Audio bitrate: 56k
- Video bitrate: 512kbit/s
- Video framerate: 30
- Dimensions: 800 x 600
This, of course, is standard definition. Most video cameras now are HD and so is the one I have for our community meetings, so the closest size would be hd 480. I have tried a lot of settings and am finally happy with the ffmpeg encoding options below. Other settings we have gone with can lose sync with video/audio and may not be optimal for your users if they have marginal internet bandwidth.
ffmpeg -i something.mov -s hd480 -ab 56k -b 512k -r 15 -ar 22050 -qscale 10 -async 2 something.flv
This basically stating
Take the input video file (something.mov) and
- size it to hd480 (852×480)
- set the audio bitrate to 56k
- set the video bitrate to 512k
- set the framerate to 15 (saves some space)
- set the audio frequency to 22050
- set the qscale to 10 (more here at Wikipedia on this)
- Sync audio and video
to get the output file (something.flv)
This seems to give us the best bang for the filesize. Hope this helps others.