I'm downloading content from the BBC website using an OSX front-end GUI app (Get iPlayer Automator) for the fairly well known get_iplayer script. The script is retrieving the flash streams from the BBC using flvstreamer (or RTMPdump?) and then converting the resulting flv file to H.264 mp4 using ffmpeg. This has been working great for a long while, until recently when the BBC tweaked the stream format. I'm now downloading content that plays back okay (audio and video) on my OSx 10.6.3 laptop, but plays audio-only (no video) if the content is moved to an AppleTV box for playback. The active H.264 codec on the ATV is Perian 1.1.4 acquired by installing aTVflash. The developer of Get iPlayer Automator has passed on the following explanation of what the BBC has done:
"What has happened is they now encode the 1280x720 stream as 1280×724 with 4 lines of bottom crop which should bring it back to 1280×720. The problem is, many players don’t understand the bottom crop directive. VLC and Adobe Media Player/Flash play it correctly. The Quicktime included in 10.6.3 plays it with a green line 4 pixels tall at the bottom. The Quicktime pre-10.6.3 and the version currently in the Apple TV refuse to play the video altogether. There is no real solution other than to hope everyone gets their players to support the bottom crop tag. That or completely re-encode every video. Note: This is not a problem with the flv-mp4 conversion."
The streams I've been downloading are 832x468, but it's the same issue. It's not clear to me whether this is a problem with the QuickTime player on the ATV, or with Perian as the active H.264 codec. This is my first foray into understanding what Perian really does so I'm a bit clueless, please excuse me if I'm not describing things right.
Are you generally aware of this issue and is it something you can shed some light upon?