Hi Eugen-Andrei, Thanks for the info. In the future you may want to post Red5 specific stuff on the Red5 mailing list. I'm including it on this response as this looks like a significant piece of information on how to resolve some syncing issues.
You can sign up for the Red5 mailing list here: http://osflash.org/mailman/listinfo/red5_osflash.org -Chris On 7/20/07, Eugen-Andrei Gavriloaie <[EMAIL PROTECTED]> wrote: > New discoveries: > > 1. The brand new flash beta player doesn't send any absolute timestamps > anymore while is publishing a composite audio/video stream. This is my > opinion, so is not 100% sure, But this is what I've discovered from my > experiments. > 2. I've discovered that flash has a crappy access time to the majority of > the video sources. Especially webcams (tested with 6 different webcams on > windows and 2 on linux). AMCAP manages to put them in [EMAIL PROTECTED] but > flash plugin doesn't. To grab a video packet out of a regular USB webcam, > flash is spending between 30 and 60 milliseconds. Add to this the time to > grab an audio packet which is between 30 and 40 and you get a value around > 100 milliseconds spent by flash to get a hold of a complete audio/video > frame (is not doing audio/video grabbing in separate threads). That is > between 9 and 15 (the best case scenario) fps. Crappy! without sound, the > things are a little bit brighter. Also linux is a little bit faster at > grabbimg packtes out of the audio video sources. > 3. FME works at another level with USB webcams. It manages to obtain a very > fast access between 0(I've seen that, maybe is something wrong with the > header sent by the FME) and 20 milliseconds. Verry good. That is why FME is > capable to achieve high fps rates. > > > Regarding our problem of audio/video sync: > > Ibrahim . did you managed to look over the red5 sources in > src/org/red5/server/stream/consumer/ConnectionConsumer.java? > IMHO this chunk of code: > > if (timestamp < 0) { > log.warn("Skipping message with negative timestamp."); > return; > } > > is completely wrong. Is executed each time a video or audio packet hits the > red5 server. It shouldn't! Audio/video frames is supposed to be dropped only > for the sake of synchronization, but not all the time. Only at the > beginning. Like FMS does. after that no frames are dropped whatsoever! With > the new version of flash player (no more absolute time stamps) red5 gets > lucky, because that condition is very rarely full filled. But is only luck. > Unfortunately I don't have time to make a patch as I've promised you > yesterday, but I'll implement my algorithm in my c++ implementation, and > I'll make it public for red5 users. So, when you have time, please contact > me > > On 7/19/07, Eugen-Andrei Gavriloaie <[EMAIL PROTECTED]> wrote: > > Forgot to attach the file... Sorry > > > > > > > > On 7/19/07, Eugen-Andrei Gavriloaie < [EMAIL PROTECTED]> wrote: > > > Finally I can get back to work! First of all I'll send you the results > of my research so we can comment on them > > > > > > You have 2 analyzing results: > > > > > > 1. traffic between fms and flash > > > 2. traffic between red5 and flash > > > > > > The tests were made as follows: > > > > > > one client is making a publish on the server (red5 or fms) and one > client is consuming the stream published by the first client. > > > > > > The columns starting with a_* are for the publisher. In those columns > I've putted the packets sent by the publisher to server (red5 or fms) > > > The columns starting with b_* are for the player. In those columns I've > putted the packets sent by the server(red5 or fms) to the player > > > > > > Some rows have NULL on b_* columns. That is because the publisher sent > the packet but the server did't sent it further to the player because the > player wasn't yet connected or whatever reason (including the bug in red5). > ignore a_id and b_id, they have no meaning in our discution. > > > > > > The other columns are as follows: > > > > > > *_content_size is the length in bytes of the payload (excluding the > header) > > > *_message_type is the type of the message transfered (either audio or > video) > > > *_payload are the first 10 bytes from the payload > > > > > > > > > The red5 problem: > > > > > > If you look at the traffic between fms and flash you can see that after > a few audio/video packets are dropped at the beginning, no more packets are > dropped. In red5-->flash traffic, ALL KEYFRAMES ARE DROPPED!!! > > > > > > My problem: > > > > > > I just want to understant the logic behind those timestamps and why > some timestamps are relateiv and some are absolute. How should I handle > them? Any clue? > > > > > > > > > Thank you so much for your interest! > > > > > > PS: > > > You can reach me via gtalk too if you want a more interactive discution, > or you can tell me what IM client you use along with your ID. > > > > > > > > > > > > > > > > > > > > > On 7/4/07, Ibrahim Y <[EMAIL PROTECTED]> wrote: > > > > okay, Thanks. > > > > and Good luck in your exams. > > > > > > > > > > > > > > > > On 7/1/07, Eugen-Andrei Gavriloaie < [EMAIL PROTECTED]> wrote: > > > > > Hi, > > > > > > > > > > Thank you for your attention! And sorry for the delay! I have a few > more days to endure my diploma exam and after that I'm free :). I will keep > you up to date > > > > > > > > > > Thank you again > > > > > > > > > > > > > > > > > > > > On 6/23/07, Ibrahim Y <[EMAIL PROTECTED]> wrote: > > > > > > Hello, > > > > > > > > > > > > how can I help or contribute ? > > > > > > > > > > > > thanks, > > > > > > Ibrahim > > > > > > > > > > > > > > > > > > > > > > > > On 6/3/07, Eugen-Andrei Gavriloaie <[EMAIL PROTECTED]> wrote: > > > > > > > > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > Based on the great work of the osflash contributors, I've > managed to develop a RTMP server written entirely in C++. But, like you > guys, I have some audio/video synchronization problems. So, I've started > analyzing following flows: > > > > > > > > > > > > > > Flash->FMS (publishing) > > > > > > > FMS->Flash(player) > > > > > > > > > > > > > > The results of the tests are now safe in the database and I > assure you they are very useful. They match the Flash->FMS audio/video > packets with the FMS->Flash packets side by side. Now I need your help guys > to get this thing working once and for good. BTW... fms DOESN'T drop any > frames!!! FMS compute the delays of the video packets from time to time. The > audio packets remains untouched!!! > > > > > > > > > > > > > > Please, let's work together on this issue and solve it. I'll > make a database export and make it available to who is interested in this > matter. > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > Andrei Gavriloaie > > > > > > > ____________________________________________ > > > > > > > Programmer > > > > > > > SQSG (www.sqsg.ro) > > > > > > > e-Mail: [EMAIL PROTECTED] > > > > > > > Mobile:+40722537658 > > > > > > > _______________________________________________ > > > > > > > osflash mailing list > > > > > > > [EMAIL PROTECTED] > > > > > > > > http://osflash.org/mailman/listinfo/osflash_osflash.org > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > Andrei Gavriloaie > > > > > ____________________________________________ > > > > > Programmer > > > > > SQSG ( www.sqsg.ro) > > > > > e-Mail: [EMAIL PROTECTED] > > > > > Mobile:+40722537658 > > > > > > > > > > > > > > > > > > > > -- > > > Andrei Gavriloaie > > > ____________________________________________ > > > Programmer > > > SQSG ( www.sqsg.ro) > > > e-Mail: [EMAIL PROTECTED] > > > Mobile:+40722537658 > > > > > > > > -- > > Andrei Gavriloaie > > ____________________________________________ > > Programmer > > SQSG ( www.sqsg.ro) > > e-Mail: [EMAIL PROTECTED] > > Mobile:+40722537658 > > > > > > -- > Andrei Gavriloaie > ____________________________________________ > Programmer > SQSG (www.sqsg.ro) > e-Mail: [EMAIL PROTECTED] > Mobile:+40722537658 > _______________________________________________ > osflash mailing list > [EMAIL PROTECTED] > http://osflash.org/mailman/listinfo/osflash_osflash.org > > _______________________________________________ Red5 mailing list [email protected] http://osflash.org/mailman/listinfo/red5_osflash.org
