On Fri, Jan 7, 2011 at 5:58 PM, Tor-Einar Jarnbjo <[email protected]> wrote: > Am 07.01.2011 23:38, schrieb David Richards: >> >> I'm also interested in another concept of lossless streaming with >> flac. Lets call it broadcast flac. A problem with streaming for long >> periods of time is that the sending and receiving computers clocks go >> out of sync, for example even if I stream myself on localhost, with > > This is not a FLAC specific problem, but has to be handled in all situations > where the streaming server is in control of the transmitting data rate. It's > caused by a playback device, which actual sample rate is slightly higher > than the sample rate actually requested or a streaming source, which system > clock is running slowly. Since these parameters (at least an exact playback > sample rate) is hard to achieve, this is a rather common problem. Or to > shorten it: If the data has a sample rate of 44100 and your sound card > consumes more than 44100 samples per "sender-time" second, your buffer will > eventually exhaust. If it's the other way around, your buffer may overflow > if the client does not handle these cases properly. >
I am well aware its not flac specific, but such a standard way of handling such a matter could be part of the packaging for streaming flac. >> Anyway what could happen is the client could do a little bit of >> re-sampling here or there to ensure its in sync with the servers >> clock. > > That is how streaming clients usually solve this problem, although is not > really improving sound quality. Its probably not a big deal if you don't resample all the time, just when your off by X amount, all of this would just be client side preferences. As long as the client side "knows" its off by X amount you could handle it in any number of ways, I'd be fine if its just crossfaded to the correct timing if was off by more than half a second, then no resampling would ever happen, you would just get a weird effect about once an hour, better than a buffer underrun or lag, or perhaps the client could look for a half second of silence and just cut it out. -David > > Tor > > > _______________________________________________ Flac-dev mailing list [email protected] http://lists.xiph.org/mailman/listinfo/flac-dev
