NAS WMV streaming issue

[Carnagerover]

Hi all,

Recently bought a Dlink DNS-323 and put to 1TB drives in for streaming media, I have the NAS connected via a Gigabit switch to my PC and when transferring files to the NAS i get around 16-17MBps and when copying off of the NAS around 19MBps according to vista.

However when i play a WMV file that i have that is 1080p from the NAS to my PC i get little pauses when watching the film, i have not watched it from the start as i skipped to the bit i wanted to watch, however once skipped forward i get little pauses in the video.

I have the NAS mapped on my PC, when i play this file on my PC i get no such pauses when i have skipped forward and it plays fine.

The computer has Gigabit connection and the specs are the following;

Quad Core Q6600 and 3.0Ghz
4GB of DDR 1066
Windows Vista

So i know that my PC is not to blame, what i cant understand is if i can write files at 17MBps and read them at 19MBps then what is causing the pauses as there is no video available that uses 152mbps i mean bluray tops out at 50mbps which is less than 6.25 MB/s

I have tried plugging the NAS into my machine directly but i still get the pauses, here is some info on the file i am trying to play;

File size : 7.84 GiB
Duration : 2h 1mn
Overall bit rate mode : Variable
Overall bit rate : 9 224 Kbps
Maximum Overall bit rate : 14.7 Mbps
Encoded date : UTC 2008-10-22 21:22:18.471

Video
Format : VC-1
Format profile : AP@L3
Codec ID : WVC1
Codec ID/Hint : Microsoft
Description of the codec : Windows Media Video 9 Advanced Profile
Duration : 2h 1mn
Bit rate mode : Variable
Bit rate : 8 542 Kbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16/9
Frame rate : 23.976 fps
Resolution : 24 bits
Colorimetry : 4:2:0
Scan type : Progressive
Bits/(Pixel*Frame) : 0.172
Language : en-us

Audio
Format : WMA3
Format profile : M2
Codec ID : 162
Codec ID/Info : Windows Media Audio 3
Description of the codec : Windows Media Audio 10 Professional - 640 kbps, 48 kHz, 5.1 channel 24 bit 1-pass CBR
Duration : 2h 1mn
Bit rate mode : Constant
Bit rate : 640 Kbps
Channel(s) : 6 channels
Sampling rate : 48.0 KHz
Resolution : 24 bits
Language : en-us

The Maximum overall bit rate is 14.7Mbps, is that to much to steam over a normal mapped share ?

Dont understand what the problem is ?

Any help would be ideal

 

[thiggins]

Vista filecopy is a specialized OS function and highly optimized. One of the things it does is launch multiple threads in parallel without waiting for each one to finish.

File streaming is a very different animal and uses only one stream. So drag-and-drop filecopy may not be a good indicator of streaming performance. But even the 1000 Mbps LAN connection read throughput vs filesize plots in the NAS Charts show 10 MB/s throughput after cache effects die out, which should be plenty for your file.

What are you using to view the file? Have you tried VLC?

 

[Carnagerover]

Hi thiggins and thanks for the reply;

I'm using Media player classic, i have the Vista codec pack as well as CoreAVC that takes care of most of my HD needs, however WMV files are decoded automatically via the WMV audio and WMV video decoders on vista.

However this file plays fine on my Popcorn Hour A-110 via an SMB share on the NAS drive so it must be something to do with Vista.

Other than streaming a file off of a SMB share though i dont know what else to use, apparently HTTP streaming is more effective than SMB but i dont know how that would work.

Does VLC use a different protocol to stream files off of a Network ?

Thanks again

 

[00Roush]

Have you ruled out video card problems? Network drivers up to date?

Does everything work correctly if you play the content locally instead of streamed across the network?

00Roush

 

[Carnagerover]

Video card drivers are the latest version, so is the network card and the file plays fine locally. It also plays on my Popcorn Hour A-110 without any hitches.

 

[thiggins]

Does VLC use a different protocol to stream files off of a Network ?

Not sure. But it's a different player with wide codec support so I thought it might allow you to narrow down the problem.

In this article I found a big difference in error sensitivity between playing a "streamed" file and one just played as a remote file.

 

[Carnagerover]

Do i need to get a more powerful NAS that can push a single stream faster than the DNS-323 can ?

I just assumed that with the 16-17MBps writing speed and 19MBps reading that i would have more than enough for streaming, however after you have explained how it works i'm not so sure now ?

 

[thiggins]

I thought you had narrowed it down to a possible Vista issue.

 

[Carnagerover]

I dont think my NAS is to blame i just wondered if it would make a difference having a faster NAS drive that could push a single stream faster. It was what you said in your post about how optimized vistas transfers are compared to simple file streaming.

It works on the same principle as Newsgroup downloading using multiple threads to speed the whole transfer up, where as that wouldnt work for streaming as it needs to be continuous and latency free.

I dont know what else to try, i have tried media player classic and VLC with no effect, other than playing the file from the shared drive i dont know of another way to stream ?

It would seem that vista isnt optimised that way, the WMV is the only one that has this problem i have many high bitrate MKV files that play fine.

 

[thiggins]

Streaming doesn't work by "push". As long as the source, network connection and player can support the stream's required bitrate (with a little headroom to spare), then the file should play.

So you are playing the file by navigating to it on the network share? That should be more robust than running from a streaming server.

Have you tried putting the file on another computer acting as a networked share and playing it from there?