More > JRiver Media Center 33 for Windows
MC media read speed problem over VPN
mattkhan:
My fault, I read server and just assumed MC as a server
Anyway, how big are the files? Try the memory option which, I think, makes it load the whole file into memory first then play it. Measure network bandwidth while it does that and see if that is faster.
Speculation.... MC doesn't adjust it's internal buffer size dynamically to account for slow networks thus isn't starting the next read far enough in advance to avoid buffering
If the problem is resolved by the memory option then the above sounds plausible (but only MC devs can say for sure)
The other Q is whether/how windows, or the server, handles network shares with respect to reading file contents, possibly this is tunable? What is the server exactly?
zybex:
--- Quote from: mattkhan on September 12, 2024, 03:20:06 pm ---Speculation.... MC doesn't adjust it's internal buffer size dynamically to account for slow networks thus isn't starting the next read far enough in advance to avoid buffering
--- End quote ---
It's possible MC is disabling the OS read-ahead with FILE_FLAG_NO_BUFFERING, or using FILE_FLAG_RANDOM_ACCESS. In this case the read-ahead buffering would need to be done properly by MC on slow networks (70ms is slow in this context).
Hendrik:
We don't disable any OS-level caching or buffering, and also read in reasonable blocks (not byte by byte). Not sure why it wouldn't manage to read even something like an audio file at a high enough bandwidth.
clarus7:
[Memory playback - load decoded file into memory] is already enabled.
I have also adjusted the prebuffering to 20 seconds. All it does is it delay the onset of buffering when playback start.
As I said, observing the bandwidth utilization when playback start, it doesn't look right. I would expect an initiate spike to fill the buffer before settling down to media bitrate.
I have attached a bandwidth usage graph capture from Task Manager to illustrate my point. Both software is playing back the same file from the same mapped network drive. The bitrate of the file is just under 5Mbps.
zybex:
--- Quote from: Hendrik on September 12, 2024, 04:12:04 pm ---We don't disable any OS-level caching or buffering, and also read in reasonable blocks (not byte by byte). Not sure why it wouldn't manage to read even something like an audio file at a high enough bandwidth.
--- End quote ---
What about the RANDOM_ACCESS flag? It was being used on the Thumbnail reader until you removed it:
https://yabb.jriver.com/interact/index.php/topic,127472.msg885286.html#msg885286
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