> I tend to disagree. It normal human conversation it wouldn't make much > sense to have 2 people talking over each other at the same time. Thus, > it most scenarios you would have only one talker anyway. Additionally, > encode->decode/mix/encode->decode isn't a very efficient CPU process for > a server, it's complicated to keep timing correct and it has a negative > impact on total latency.True, but there is one critical place where it's necessary to mix at least two streams--when someone's trying to break into a stream. If speaker A goes on and on and speaker B (or C, D, E, F...) wants to interject or interrupt, who do they do it without inband without mixing?> The overhead required to mix merge and re-encode is usually not worth > the benefit as in most situations you are not really saving any > bandwidth.But the options are *don't transcode* and *always transcode*. Switching between them is difficult to do on the fly. The 'obvious' solution seems to be run N processes to detect 'speech' or important audio content on the incoming N streams. Pick on or two that need output, then mix and recode them. If the detection is done in the client, then the servers job is much simpler--arbitrate, mix, and encode. Since the overlap periods of the mixing are going to be infrequent and discontinuous, you don't have to be sample exact--no stream synchronization required. So, I'd say any maching that can decode two streams, encode one stream, and do a little overhead should be able to act as a server. Hey, the client has to be able to encode in speex in real time, anyway, why waste that effort? Cheers, David --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'speex-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
Hi Allen,> I tend to disagree. It normal human conversation it wouldn't make much > sense to have 2 people talking over each other at the same time.One of the problem is, that if the server doesn't distribute the stuff, then one entity must send the stream to every other entity. That could work fine with fast connections, but doesn't work with a modem connection. My mother have onl< a 33K6 connection. I dont want here to use this bandwith ONLY to send identical audio packages to different entitys. BTW: The server should only merge stuff, if it is necessary. Some people need fideback like hmmm, aaah, oooh etc ;-)). Others say allways : ja .... ja....jo.....yes.....ja...oooh ;-)) And The others say ... yes, but .... yes, but... no, because.... You need this feedback. People are iritated if the call someone how have a phone that mutes in nobody is speaking. Youz have the feeling that you speak with a wall. That's it. > Thus,> it most scenarios you would have only one talker anyway. Additionally, > encode->decode/mix/encode->decode isn't a very efficient CPU process for > a server, it's complicated to keep timing correct and it has a negative > impact on total latency.True, but unless you change The internet, there are not much posibilities.> The overhead required to mix merge and re-encode is usually not worth > the benefit as in most situations you are not really saving any > bandwidth.Sure you do and you must do, because elsewhere it doesn't go through the pipe. <p>Best Regards, <p><p>Carsten --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'speex-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
Hi all, <p>once again i came up with my conferencing stuff. On a conference with more then two people it's a waste of bandwidth, that every entity send it's data to every entity. Since there is only one audio line, the audio must be merged on the server. Here are my questions: - How many audio chanels can a server process (let's say a 3GHz machine) in this way: decode all speex chanels, merge them into one chanel and then encode the result again? This means that some chanels are merged to one chanel and this multiple. - Could aditional DSP-PCI-Boards help to do this? - Is it posible to merge without decode? Any help is welcome. Thanks, <p><p>Carsten Breuer <p><p><p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'speex-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
I tend to disagree. It normal human conversation it wouldn't make much sense to have 2 people talking over each other at the same time. Thus, it most scenarios you would have only one talker anyway. Additionally, encode->decode/mix/encode->decode isn't a very efficient CPU process for a server, it's complicated to keep timing correct and it has a negative impact on total latency. The overhead required to mix merge and re-encode is usually not worth the benefit as in most situations you are not really saving any bandwidth. -----Original Message----- From: owner-speex-dev@xiph.org [mailto:owner-speex-dev@xiph.org] On Behalf Of Carsten Breuer Sent: Thursday, November 20, 2003 1:56 PM To: speex-dev@xiph.org Subject: [speex-dev] Server based audio merge Hi all, <p>once again i came up with my conferencing stuff. On a conference with more then two people it's a waste of bandwidth, that every entity send it's data to every entity. Since there is only one audio line, the audio must be merged on the server. Here are my questions: - How many audio chanels can a server process (let's say a 3GHz machine) in this way: decode all speex chanels, merge them into one chanel and then encode the result again? This means that some chanels are merged to one chanel and this multiple. - Could aditional DSP-PCI-Boards help to do this? - Is it posible to merge without decode? Any help is welcome. Thanks, <p><p>Carsten Breuer <p><p><p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'speex-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered. <p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'speex-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.