dgalvan123 said:
When you Airplay footage that you just recently shot on your iphone (be it 4 or 4s) you are sending raw, uncompressed video data over your wifi network to the ATV2.
Do you have a citation for that?
Ok, let me correct myself because the part you quoted may indeed be untrue: I don't actually know if the iPhone is compressing the video before it Airplays it over the wifi network or if it is sending the uncompressed data, as I mentioned at the end of my previous post (sorry for the confusion).
BUT what is really relevant to this discussion is this: The bit rate of the HD video you took on your iphone4 or 4s is much higher than the bit rate of videos you can get from, say, the iTunes store. That higher bit rate is likely the reason that Apple didn't allow airplaying of your camera-roll videos when it first introduced Airplay last year. See this post from John Gruber, or search around in the Macrumors and Apple.com forums for complaints about camera roll videos not being airplay-capable. This was back in November of 2010.
Here' an example thread of people complaining about the lack of Airplay support for IP4 camera roll videos last year:
https://forums.macrumors.com/threads/1052843/
From:
http://daringfireball.net/2010/11/airplay_limits
"HD movies rented or bought from iTunes tend to be encoded with bitrates of about 5 Mbit/s. Video clips shot on the iPhone 4 have bitrates of about 10-11 Mbit/s the iPhone doesnt have the processing power to compress movies tighter than that. "
This led to people developing third-party apps that would take a video from your camera roll and airplay it to the Apple TV2, even though the iPhone 4 couldn't do that natively before iOS 4.3.
ex: Air Home Video
http://www.iclarified.com/entry/index.php?enid=13087
or Quickplay
http://itunes.apple.com/us/app/quickplay-for-airplay-for/id409680873?mt=8
These third-party apps worked by taking the video, compressing it (which took about the same amount of time as the clip length itself), and then airplaying the lower-bit-rate version to the ATV2 without a problem.
Of course, with iOS 4.3 in March of this year, Apple DID enable airplaying of the 720p iPhone 4 video from the camera roll, and everyone noticed how slow and clunky that airplay process could be, presumably due to the higher bit rates.
Here's a macrumors thread with people complaining about that, back in March of this year (2011)
https://forums.macrumors.com/threads/1113042/
And here's an apple.com forum with people complaining about the lack of airplay capability, then discovering the third-party apps, then getting native airplay
https://discussions.apple.com/thread/2656393?start=75&tstart=0
Sample comment from that thread on March 16:
"However, even for a 50sec video it takes 30 seconds of buffering making the whole process really slow and annoying."
To sum up: When the iPhone 4S airplays the camera roll videos it is probably doing some kind of compression to send those to the ATV2, I agree. But I still say that a 1-minute video at 1080p is going to be bigger than the same-length video at 720p, compressed or uncompressed. And since the iPhone 4 videos at 720p require a significant wait as it is, it's no surprise that the iPhone 4S airplay experience requires even a longer wait, more buffering, or more dropped frames.
Surely uncompressed 1080p will be so far over 54mbit/s that it's totally unfeasible.
*shrug* I dunno. You can find out, though, by downloading a 1080p video from your iPhone 4S to your computer, and looking at the specs of that video in Quicktime or iTunes. That will tell you the bit-rate.
And what's wrong with just bit streaming the MP4s anyway?
Not sure what you mean here. . . but I can give you some anecdotal "evidence" regarding streaming 1080p to my ATV2.
I don't have an iPhone 4S, but I do have a DSLR camera that shoots 1080p video. When I connect my camera to my mac, those videos get imported into iPhoto, and iTunes serves them to my Apple TV2. Some of these high-quality movies (the ones shorter than say, 1 minute) play successfully on the Apple TV, after a LONG buffering period (usually longer than the length of the clip itself). Some of the longer movies (>1 minute) buffer for a while, and then simply crash the Apple TV2 without actually playing. That's if I leave the videos untouched in iPhoto as .mov files. If I drag the movies into iTunes and let iTunes automatically convert/compress them using H.264, the movies play fine on my apple tv 2, but they still take longer to buffer than my iPhone 4 (720p) videos of similar length.
