[mythtv] Possible playback scenarios for the iPhone

Chase Douglas chasedouglas.lists at gmail.com
Fri Jul 18 22:58:14 UTC 2008

I am interested in developing a frontend for the iPhone with live tv  
playback, but there are two hurdles along the way:

1. Content is encoded in the format coming from the tuner device, and  
as far as I am aware, no tuning device outputs an iPhone compatible  

2. The iPhone SDK (I'm trying to keep this under Apple's terms as  
well) has no streaming video support. At best, it can take a static  
file and stream that from a URL, but there's no support for streaming  
mutable content like an rtsp:// stream. A further complication is  
Apple's insistence that developers cannot access the framebuffer.

The first issue could be remedied through live transcoding before  
streaming to the device. This isn't implemented yet, but is possible.  
The second issue is a much higher hurdle. Without the ability to play  
streaming content within the SDK, the only way this could work is  
through software decoding and playback through either a quartz  
graphics layer or an opengl layer. I've never written any rendering  
software but I know it's possible. My question is: would the iPhone be  
powerful enough for a reasonably encoded stream to be played back? By  
reasonable, I'm thinking standard mpeg-2 or the mpeg-4 encoding, but  
keeping in mind that I'll have no access to the hardware acceleration  
already present on the iPhone.


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