Apple policy for http live streaming apps

问题:

Here are the requirement for apps which need take the http live streaming technology,

If your app delivers video over cellular networks, and the video exceeds either 10 minutes duration or 5 MB of data in a five minute period, you are required to use HTTP Live Streaming. (Progressive download may be used for smaller clips.)

If your app uses HTTP Live Streaming over cellular networks, you are required to provide at least one stream at 64 Kbps or lower bandwidth (the low-bandwidth stream may be audio-only or audio with a still image).

These requirements apply to iOS apps submitted for distribution in the App Store for use on Apple products. Non-compliant apps may be rejected or removed, at the discretion of Apple.

What is the real purpose to set up the limitation with 10 minutes or 5MB in 5 minutes ? And what is the reason to use those two specific data ? Why set the threshold value as 64 kps ?

回答1:

I think this is done with the aim of encouraging Adaptive video bitrate streaming with respect to progressive download.

In the case of progressive download, a large video can potentially consume all the amount of available data on a mobile device. With Adaptive streaming you watch only the part of the video in which you are interested.

Moreover with adaptive streaming, the video sending rate is adapted to the available bandwidth. To this purpose, in the case of very slow mobile connection, i.e. GPRS, the stream encoded at 64 Kbps can still be streamed.