Compressing/Resizing ALAsset video on the iPhone before uploading

Question

I've built an app that uploads videos from the iPhone (uses the ALAsset libs, not the built in photo/video pickers, for selection) to my web server which then compresses/encodes them. This works great, but files get big very quickly with longer videos. Is there a standardized way to compress/downsize these videos right on the device before I handle the uploading? Is it worth the CPU hit? Does the AV Framework support this? Or do I have to use something along the lines of ffmpeg? I'm looking to go from 1280 x 720 to about 516 x 290. I could save a lot of bandwidth by handling this on the device first, just not sure of my options despite a lot of searching.

Answer 1

Take a look at AVAssetExportSession and it's methods. Then use the preset AVAssetExportPreset640x480 or one of the other presets to resize from 1280x720 to something smaller. A custom size (like 516x290) is at the moment not possible with AVAssetExportSession.

Cheers,

Hendrik