DynamicStreamingResource and Error: Playback failed with certain media

Question

I'm running into an issue with a DynamicStreamingResource wherein, with certain media, I receive a Playback failed error after about 20 seconds of playback. The error does not appear with these assets, which play back perfectly:
_dynamicStreamingResource = new DynamicStreamingResource("rtmp://cp67126.edgefcs.net/ondemand");
_dynamicStreamingResource.streamItems = Vector.<DynamicStreamingItem>(
[ new DynamicStreamingItem("mp4:mediapm/ovp/content/demo/video/elephants_dream/elephants_dream_ 768x428_24.0fps_408kbps.mp4", 408, 768, 428)
, new DynamicStreamingItem("mp4:mediapm/ovp/content/demo/video/elephants_dream/elephants_dream_ 768x428_24.0fps_608kbps.mp4", 608, 768, 428)
, new DynamicStreamingItem("mp4:mediapm/ovp/content/demo/video/elephants_dream/elephants_dream_ 1024x522_24.0fps_908kbps.mp4", 908, 1024, 522)
, new DynamicStreamingItem("mp4:mediapm/ovp/content/demo/video/elephants_dream/elephants_dream_ 1024x522_24.0fps_1308kbps.mp4", 1308, 1024, 522)
, new DynamicStreamingItem("mp4:mediapm/ovp/content/demo/video/elephants_dream/elephants_dream_ 1280x720_24.0fps_1708kbps.mp4", 1708, 1280, 720)
However this set of assets do not work:
_dynamicStreamingResource = new DynamicStreamingResource("rtmp://flashstream.adobe.com/ondemand");
_dynamicStreamingResource.streamItems = Vector.<DynamicStreamingItem>(
[   new DynamicStreamingItem("mp4:flash/m/mv1/acom/connectnow/flvs/acom014_854x480.flv", 408, 854, 480)
, new DynamicStreamingItem("mp4:flash/m/mv2/acom/connectnow/flvs/acom014_854x480.flv", 608, 854, 480)
, new DynamicStreamingItem("mp4:flash/m/mv3/acom/connectnow/flvs/acom014_854x480.flv", 908, 854, 480)
I've confirmed that each asset individually plays as desired, which they do.
Additionally, I have noticed that the buffer grows at an awkward rate - it jumps to about 10 seconds, stutters back and forth between 15 and 20, then stalls, and eventually jumps to 40 seconds, at which point the playhead, around 20 seconds, stalls and I receive the Playback failed error. This happens 100% of the time.
Any thoughts as to why the second set is problematic?
Thanks!

Answer 1

I'm getting "NetStream.Play.StreamNotFound" when I try to play your first stream so I'm not able to investigate this. Here are some things to look at:
The bitrate you give to DynamicStreamingItem is very important. It must be accurate with regard to the encode. The switching rules use this value to throttle the connection between client and server to keep the buffer from growing too large. Make sure your encodes are CBR and not VBR (variable bitrate). Make sure all encodes have the same keyframe interval. Make sure you set your buffer to 8 seconds initially to get this working. You can adjust if you wish.
Also, turn logging on and start digging through the logs. Determine which stream playback is failing on. The next thing I would try is put the bitrate in the stream name and put them in the same location on the server rather than different paths for each bitrate.
Thanks,
- charles