Issues with iPhone Http Streaming with concatenated video files

We are seeing this when "tying" two video files together.

Example we have Ad video that is segmented and content file which is also segmented. We create a new file which has both Ad and content segment information together. However we are seeing an issue where either the Ad content is truncated or the content starts having A/V sync issues. Both ad and content are segmented the same way , 5 sec segmentation. however since Ads are variable length the result file may have left over segment something like:

#EXTM3U
#EXT-X-TARGETDURATION:5
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:5, 
fileSequence6.ts
#EXTINF:5, 
fileSequence7.ts
#EXTINF:4, 
fileSeque开发者_开发问答nce8.ts
#EXTINF:5, 
fileSequence0.ts
#EXTINF:5, 
fileSequence1.ts
#EXTINF:5, 
fileSequence2.ts
#EXTINF:3, 
fileSequence3.ts

Is this the proper way to play 2 files one after the other without rebuffering? should generate-variant-plist be used to a play list of 2 files?

---

When you have a break in the stream to switch to a commercial, ad, or alternate video source then you want to introduce the discontinuity tag before the start of the next segment, for example:

#EXTM3U
#EXT-X-TARGETDURATION:5
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:5, 
movie0.ts
#EXTINF:2, 
movie1.ts
#EXT-X-DISCONTINUITY
#EXTINF:5,
commercial0.ts
#EXTINF:5, 
commercial1.ts
#EXTINF:3, 
commercial2.ts

This gets a little more complicated if you encrypt the streams because they use progressive encryption based on the prior segments encryption state and the sequence number which come together to form an "Initialization Vector". If you break the stream you have to reset the initialization vector so that the encryption/decryption can continue uninterrupted. This is an involved process so best to just search on Initialization Vector in Apple's docs.