Hi Sebastian, FFMPEG link was a great help, Thanks.
I've few questions, Is quality of low, medium, and high bandwidth streams constant? i.e. like in youtube if the original is at most 720p then subsequent predefined lower qualities are available e.g. 480p, 360p etc. Or is it we always try to create three streams as high, medium and low starting from the original as high? IMHO former approach is better as the implement is easier and the outcome is always predictable. What do you think? Where can I get the video settings sent from the client side and server side in OpenMeetings? I'm going to start writing the proposal very soon which I'll improve gradually until the deadline. Anything you want me to focus on and any suggestions? Thanks Khyrul Bashar On Tue, Mar 15, 2016 at 3:11 AM, [email protected] < [email protected]> wrote: > Hi Khyrul, > > I think there are some interesting aspects of this task. I think your > approach in general sounds good, and you are right, the latency will be a > major bottleneck for the solution. > > Around FFMPEG real time transcoding you might want to look at: > https://trac.ffmpeg.org/wiki/StreamingGuide > > So it might be possible to simply re-stream the stream from Red5 to FFMPEG, > FFMPEG transcodes it and publishes it again, and you re-stream from FFMPEG > to Red5 then to the conference room. > > Thanks, > Sebastian > > 2016-03-14 21:51 GMT+13:00 khyrul Bashar <[email protected]>: > > > Hy, > > Sorry if it's a duplicate. I've sent previous one before subscribing. I'm > > Khyrul Bashar, 4th year CSE student from Bangladesh. I've participated > > successfully in GSoC-2015. I've coded the PDFDebuuger app of PDFBox > project > > in apache foundation. > > This year I hope to code Openmeetigns-550. I find it an interesting > problem > > but to solve available documentation resources is almost none like the > > issue says "there is hardly any documentation on that available in the > > internet". So far I've build the OpenMeetings source code and gone > through > > the source code in brief. > > I'm trying to understand how the Openmeetings conference live streaming > > works. This is I've understood so far, in client side flash 'publish' the > > media and in server side that other clients in same scope is made aware > > about the video. ScopeApplicationAdapter class which has extended > > ApplicationAdapter class of Red5 gets notified on a new video stream in > > 'streamPublishStart' method. And from there Openmmetings messages other > > concerned clients via their 'Connection'. In flash client side upon > > receiving the message the video is playback. All the necessary url, port > > are stored in 'FlexGlobals.topLevelApplication', One thing I don't > > understand how "FlexGlobals.topLevelApplication" data are populated in > the > > first place. Pardon me if it's trivial, I've read the ActionScript code > > today for the first time. > > Now my understanding of the issue is, we have to implement a way so the > > video published by the client is available in three resolution (low, > > medium, high) to other clients in the same room. As red5 takes care of > > handling the live streaming itself(it's my understanding), to make any > > versions of the video but original available we need to intervene in the > > middle. e.g. like recording we add stream listener and from there data is > > pulled using 'StreamPacket'. From this, we make an input for an FFmpeg > > command which gives us transcoded videos as our requirement. Then those > > outputs are relayed to other clients according to their demand. > > I'm concerned about this approach as there is a real chance for latency > as > > one more step is added in the middle. Again as for the last three days, I > > spent most of the time just to understand red5 and yet not really > confident > > (thanks to red5 documentations!), I haven't really chance to look at > FFmpeg > > workings, so I'm not sure, how the data received from the client is made > > available to FFmpeg to transcode. I would appreciate some guidance here. > > Please feel free to correct my understanding of the problem and > application > > architecture. > > > > Thanks > > Khyrul Bashar > > > > PS: Why Red5 documentations are so rare? I'm not complaining just > curious. > > Red5 seems a decent media server used by many e.g. facebook. > > > > > > -- > Sebastian Wagner > https://twitter.com/#!/dead_lock > [email protected] >
