Apple TV

[Andy Bircumshaw]

On 1/11/2010, at 6:36pm, Christian Hewitt wrote:
> ... get_iplayer uses ffmpeg to move flash video into an mp4 container so it's not impossible to change the ffmpeg commands to include cropping that resets the video dimensions to what the crippled QuickTime player can handle. The negative to this approach is that you perform a full re-encoding of the video file. Instead of a quick 2 minute swap of container formats it can take an hour or more to re-encode longer shows. I did some experimentation before and cropping is what you need. I can't remember the exact commands though - I ran out of patience and moved on to other ideas ...

I'm not sure that cropping is required, as such. See also my other post, but in the comments on one of the pages of Phil's site, Andy (ctrl-f "apple") claims to have been able play other 1280×720 movies: 
   http://linuxcentre.net/bbc-iplayer-hd-1280x720-now-supported-by-get_iplayer

He notes that iPlayer's HD recordings have 188Kbps audio and that Apple TV will play up to 160Kbps. That transcoding is cheap in processor cycles.

I'm sure you know this, but to elaborate on your first sentence for the benefit of Ian or anyone else: get_iplayer uses the ffmpeg program to remux video from the flash video container (.flv) used by the BBC to an .mp4 container. Remuxing does not change the video (or audio, as applicable) in any way, so it is a quick process and the results retain original quality, codec and approximate file size. iPlayer's hi-res and HD shows use the h264 video codec, AAC audio. Transcoding means to change the video (or audio) stream by re-encoding it; this is done typically to make the file / resolution smaller or so it can be played on a device with a less-powerful CPU or which doesn't support the original codec. You can use the original codec when transcoding, or a different one; transcoding takes longer and it always results in some quality loss (although sometimes on may not notice the loss).

aB.