Unexpected autoDASH behavior
I’m very new to video streaming and EMS (less than a week), and I’m a bit confused about autoDASH and DASH streaming in general.
I am trying to create a similar environment as odoell in this post, except that I am trying to use autoDASH to create a DASH stream for in-browser playing whenever a pullStream is executed on a local .mp4 file. It seems to work except that the beginning of the video is cut off and I cannot seek through the video. I understand that a DASH stream manually created after a pullStream will only create segments for the video after the point of creation, but it seems like that would make autoDASH useless for VOD, since by definition the DASH stream is created after the pullStream. Perhaps I am misunderstanding the usage of AutoDASH?
Additionally, when I try manually creating a DASH stream first, then executing pullStream on a local .mp4, giving it a matching localStreamName, neither one appears in the web UI, nor are any expected files created in /var/evo-webroot. Which makes me wonder how creating a DASH stream before pullStream is supposed to work, since a DASH manifest contains a great deal of information specific to the file being streamed (codecs, etc). How would a DASH stream created before pullStream contain this information? Will EMS alter the manifest of the DASH stream when pullStream is executed? It didn’t seem to in my case.
As a side note, the links in the pullStream section of the documentation for the rangeStart and rangeEnd parameters (http://livedocs.adobe.com/flashmediaserver/3.0/hpdocs/help.html?content=00000185.html) seem to redirect to a generic help page with no information on start/len parameters.
I would greatly appreciate any help!
1 Answers
As I continue learning, I think I have figured out how autoDASH works, but I am still unable to achieve my goal. I can create DASH streams from local streams after executing pullStream, but when I open the DASH stream in a browser it seems to start playing from wherever the local stream happened to be in its playback, as if playback had started right when I executed pullStream (if I open the same pulled local stream in VLC it starts from the beginning of the file no matter what, and I can seek as normal). The video then freezes almost immediately, while the audio continues to play normally. The DASH player also lists some huge number for the time remaining in the video (162,254 hours), and I cannot use the seek bar to change my position. It seems from odoell’s post that perhaps DASH segments are generated in real time, which will not be useful to me, so hopefully it is not the case!