Direct Stream Memory Buffer


#1

The descritpion of the Direct stream is not clear in whatt concern the buffering of the input digital stream.

From my NAS I can download music much faster than realtime play, however with many DACs sound turns OFF when there is a transitory problem on the internet communication. This could be solved easily if the audio data stream is bufferized for a few seconds, it means downloading the data in advance once a song is selected. Is this feature included in the Direct stream? If yes, how long in music reproduction seconds is it at the fastest data rate? Without a buffer I am not sure to understand the usefulness of reclocking the data.

Cheers, Juan

PS I searched on the forum if this question arised before, but nothing found…


#2

There’s a significant memory buffer in the bridge if you use that for just the reasons you mention.

The size of the buffer needed to reclock lower jitter is much smaller - clocks are off by, say, 10 - 50 ppm (parts per million). The buffer just has to have enough samples to cover the amount of time that it takes for the local clock to change to a new value, lets say from 100 ppm too slow to 100 ppm too fast. So even at 196k and over one second 200 ppm is only 40 samples…

If you play over S/PDIF, AES/EBU, TOSLink, I2S or USB the memory buffers are in the playing software - I keep my queue ahead buffer at 16 seconds or so, so that my external drives have time to spin up before a track transition. I keep my ASIO, WASAPI or whatever buffers at their maximum size (say 500ms.) as well. Small buffers in the drivers are for real time recording work. This is plenty of time for any reasonable PC interrupts, etc.