When a disc volume (USB hard-drive or thumb-drive) is connected to the BDP-1 Digital Player we are transferring raw digital computer data and not streaming audio from that drive. In other words, we are extracting digital bits without any worry over file corruption or inducement of "jitter" to the file.
James,
A couple of questions. I don't quite follow what you're saying in the above paragraph in regards to "transferring raw digital computer data" and "not streaming audio from that drive." You're using MPD (music player daemon) with locally mounted media. MPD does not yet have the facilities to load an entire song into memory, and in a stock mpd configurations file (mpd.conf) the default audio buffer size is 2048 KiB. From the mpd.conf man page:
audio_buffer_size <size in KiB>
This specifies the size of the audio buffer in kibibytes. The default is 2048, large enough for
nearly 12 seconds of CD-quality audio.So, in essence, we are streaming data from the USB media device, over time, to fill MPD's audio buffer and be decoded. This is true for locally mounted files or files fetched over the network. Or have you made modifications to the MPD source code?
And, why would there be "jitter" introduced or "file corruption" when copying digital data from USB media?
We are processing “Raw Digital Data” at the USB input on the BDP-1 and sending it through a buffer to the internal CPU. We are not streaming Audio Class 1 or Class 2. By the way, the concern and discussions you hear about regarding asynchronous versus synchronous with USB inputs has to do with the use of the USB to stream audio class one or two from a Source to a DAC. These concerns do not have any effect on the use of USB to transfer data from a storage device, thumb drive or hard drive, to the CPU over the USB bus like in the Bryston BDP-1 Digital Player.
Yes, true. But the last sentence in this paragraph seems to contradict what you said about file corruption and jitter in the digital data stream in the previous paragraph. Perhaps I'm misunderstanding something?
Lastly, you're using Linux and music player daemon which is GPL software. Searching your website, I could not find any source code posted. Where can I find them?
Thanks,
Nick
