# iOS Adaptive Bit Rate streaming using Smil file problems
**URL:** https://community.wowza.com/t/ios-adaptive-bit-rate-streaming-using-smil-file-problems/37381
**Category:** Wowza Streaming Engine
**Created:** [May 23, 2012, 1:32pm UTC](https://community.wowza.com/t/ios-adaptive-bit-rate-streaming-using-smil-file-problems/37381 "2012-05-23T13:32:37Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Grant\_Keiser](https://community.wowza.com/u/Grant_Keiser)
#### Post date: [May 23, 2012, 1:32pm UTC](https://community.wowza.com/t/ios-adaptive-bit-rate-streaming-using-smil-file-problems/37381/1 "2012-05-23T13:32:37Z")
Hi,
We are using transrate.xml to create three versions of the stream, at bit rates of 150, 300, and 1000 kb/sec. When attempting to use a smil file which has these three streams on iOS devices the stream jumps back in time by several seconds when switching to the highest quality stream. Are these streams not synced unless we use the ngrp method of adaptive bit rate streaming, or is there some other problem that would be causing this? We have had problems using ngrp and switched to smil files.
The 1Mb stream is 640 x 360, the 300kb stream is 416 x 234, and the 150kb stream is 320 x 180.
Thanks,
Grant
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### Author:  [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)
#### Post date: [May 23, 2012, 7:42pm UTC](https://community.wowza.com/t/ios-adaptive-bit-rate-streaming-using-smil-file-problems/37381/2 "2012-05-23T19:42:31Z")
Grant,
Have you seen this method of generating a smil file?
[https://www.wowza.com/docs/how-to-create-and-play-smil-files-with-streams-created-by-wowza-transcoder](https://www.wowza.com/docs/how-to-create-and-play-smil-files-with-streams-created-by-wowza-transcoder)
The encoding details in this smil is most useful to iOS, and might improve playback.
Richard
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### Author:  [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)
#### Post date: [May 23, 2012, 8:18pm UTC](https://community.wowza.com/t/ios-adaptive-bit-rate-streaming-using-smil-file-problems/37381/3 "2012-05-23T20:18:38Z")
Cool, you’re welcome. Thanks for the update
Richard
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### Author:  [@Grant\_Keiser](https://community.wowza.com/u/Grant_Keiser)
#### Post date: [May 23, 2012, 1:53pm UTC](https://community.wowza.com/t/ios-adaptive-bit-rate-streaming-using-smil-file-problems/37381/4 "2012-05-23T13:53:40Z")
I have seen it, but it always worked fine with just the bit rates in the file for us (typically with just the medium and low streams). I will try that and let you know, thanks again.
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### Author:  [@Grant\_Keiser](https://community.wowza.com/u/Grant_Keiser)
#### Post date: [May 23, 2012, 2:13pm UTC](https://community.wowza.com/t/ios-adaptive-bit-rate-streaming-using-smil-file-problems/37381/5 "2012-05-23T14:13:33Z")
The problem seems to have gone away with the more detailed smil file, thanks!