Stuttering on M2TS - Any Soltuions please?


#1

Hi - I am new to this and have been searching the forums for a probalem that I’ve got which other user seem to have experienced. Basically I have my desktop, router and WDTV live connected via powerline (200mb). My Powerline utitlity software tells me I am getting approx 120mbs. I can view normail rpipped DVD from my desktop (which is in another room) but my M2TS files play ok for approx 30sec and then stutters heavliy and I lose the sound. When connected to the USB link directly to an external drive, it plays fine. Please can someon help or direct me to where I may be able to look/tweak my set-upand hopefully the solution. Thanks


#2

In this months maximum PC mag they have the box opened up an review the hardware inside.  In the box you have 1 GB or mem - 512 for the WD os.  That leaves just 512 for caching.  Your file is pushed in at a rate of 4+ sec to replace the 512 and the box is using it up faster then you can push it. 


#3

Try without the powerline using regular ethernet and see if that resolves the issue.  You may be getting some network problems using the powerline.


#4

Hi, yes - M2TS has been a problem for me for several months - but it has not been the WDTV live that’s been the issue - it has been network bandwidth availablility. I also use powerline (D-Links) that gives me a theoretical 100mbps, but this reduces down (by ~ half or more) when the powerline encryption is added - as well as noise/interference on the mains circuit.

Hold this next thought until you read the next sentence - 120megabits/ps is *theoretically* a raw 15MegaBytes/ps on a fixed line LAN connection.

Now consider that a lot of DVD media is stored for a transfer rate of ~=<9.5MegaBytes/per-second.

Now consider that a lot of HD/Blu-Ray/M2TS media is stored for a rate of ~=<30MegaBytes/per-second.

This may give you a clue as to why DVD media is fine and M2TS/HD media is stuttering - you just probably don’t have the bandwidth. For HD streaming you need to be looking at 1gbps fixed line LAN for good, unfettered performance.

I even tried this over 300mbps wireless with numerous different configurations and could not get a satisfactory result for M2TS streaming - so I am  going to have to resign myself to either running a cable directly to the unit or shuttling the MT2S media via USB drive between source and player.

I know that I can get “viewable” performance for M2TS/HD media over a dedicated 100mbps fixed line LAN - as there is no noise, no data encryption etc - but I haven’t extensively tested that scenario…

Hope that helps?

Cheers.


#5

Thanks for your replies

What’s puzzling me is I am registering 120mb connection to my powerline adapter. When I replaced it my a 20m ethernet cable, I only got 100mbs. By your measurements I should have good quality video. A CAT5 ethernt is 100mb isn’t?

Sounds like I won’t be able to get what I want from the 200mb adpaters, haa anyone tried the belkiln 1 gigabyte ones? if so I’d be interested in knowing if this will do the trick.


#6

Hi - well a CAT5 cable is the standard for 100mbps LAN interconnects. Cat5e should be able to take you to a stable 1gbps if the router is also gigabit capable. Unfortunately, the wdtv-live isn’t gigabit capable - but having the router being gigabit capable does make a difference for me.

So for my tests, I typically use a gigabit capable media server/DLNA NAS with a gigabit router. I’d then “plumb” the wdtv-live into that router. I ended up using a higher spec router as my all-in-one adsl/lan/wireless router had not been up to the job at all - it just couldn’t deal with intensive network activity.

If you’re just testing with the PC & wdtv-live with a router in between - and little or no other activity - then 100mbps should give reasonable HD throughput.

But, other considerations are things like the duplex mode of network adapters and whether they are indeed connecting at 100mbps full duplex. you can check that on one of the the router config pages typically.

Another consideration is your method of accessing the MT2S files - is it network share or media server? SMB/CIFS shares are not very efficient for high throughput media applications - hence why I use a DLNA server to stream directly between source and player.

And I need to ask the question - have you checked whether these same M2TS files are fine if accessed using an external USB drive attached to the wdtv-live?


#7

Thanks Mystere, I have following hadrware: 1) reasonably high spec desktop, 64bit vista with gigbait ethernet connection. 2) Netgear wireless n router with 100mb ethernet connection. 3) WDHD TV Live tried the following 1) Hardwire (cat5) desktop to router and powerline from router to wdtv. 2) powerline desktop to router and powerline to wdtv I do not have a ethernet wire long enough for direct desktop to wdtv. do have a small NAS server coming with media server software on it so will try that whan it arrives. For some reason, I am actually registering higher speeds with powerline (by approx 20mbs) than with ethernt connections. I am also using network share rather than media server (this will be my next test, but I’m not hopeful) to answer your question re USB. I have attached an extenal drive to the WDTV and the M2TS media plays absolutley perfectly. I am hoping you see somtheing glaringly obvious in the info I have provided that I would not due to my limited experience in this area. Thanks


#8

Actually you should try with a media server now, the WDTV live is pretty lame when it comes to pulling content with high bitrate from a network share. On my fast ethernet network it barely reads at more than 20-25 MB/s, whereas TVersity / Twonky easily push the video at whatever rate is required (I’ve done some tests with sustained bitrates of 50+ MB/s, no problem via media server).


#9

Many Thanks - will try it and update you.


#10

mystere wrote:

Now consider that a lot of DVD media is stored for a transfer rate of ~=<9.5MegaBytes/per-second.

Now consider that a lot of HD/Blu-Ray/M2TS media is stored for a rate of ~=<30MegaBytes/per-second.

    • *> I think that your are mixing bytes an bits, 1 byte = 8 bits.> Bluray spec is 54mbit/s max according to wikipedia. From my own tests, seems that the WD is limited to 50mbit/s over samba while it can cope with 70mbit/s constant bitrate files over DLNA (tests done using no wifi, no powerline, all wired to a Synology NAS using samba shares and synology DLNA server)

#11

@dex38

Hi - not really mixing any bits or bytes - just basing it on  information passed to me previously and data rates seen stored on BD media.

We all have our own experiences I guess.

http://www.blu-ray.com/faq/#bluray_speed


#12

@cavalier

Yes - personally it sounds like your going to have to go down a media server route for the most effiecient media transfer.

You can achieve this either with a media server on your pc, a decicated NAS/media server or use a USB drive to shuttle the movie when required.


#13

mystere wrote:

 

Hold this next thought until you read the next sentence - 120megabits/ps is *theoretically* a raw 15MegaBytes/ps on a fixed line LAN connection.

Now consider that a lot of DVD media is stored for a transfer rate of ~=<9.5MegaBytes/per-second.

Now consider that a lot of HD/Blu-Ray/M2TS media is stored for a rate of ~=<30MegaBytes/per-second.

 

This may give you a clue as to why DVD media is fine and M2TS/HD media is stuttering - you just probably don’t have the bandwidth. For HD streaming you need to be looking at 1gbps fixed line LAN for good, unfettered performance.

 

 

Thats where you got your mix-up with bits and bytes. The DVD and Blu-Ray rates should be in ‘bits per second’ (Mbps) not bytes. 

http://en.wikipedia.org/wiki/Bit_rate#Video

Your own link also shows this.

http://www.blu-ray.com/faq/#bluray_

Everything is expressed in Mbps (mega bits per second)

http://en.wikipedia.org/wiki/Data_rate_units#Megabit_per_second


#14

Hi All, Thanks very much for all your comments and advice. As it turned out, the playback from the media centre (Twonkymedia) - as oppposed to a network - was fine using powerline, I even tried it out on two diferent machines. The second one was stuttering slightly. I have no problems having two streams only if one is HD and the other is a rippid DVD. I am now going to upgrade my router. For my next trick, I am hoping to resolve the stuttering on the second computer by attaching a new powerline network from the router. Hopefully this will go some way in resolving he problem coupled with my router upgrade. Now, Twonky Media seems to work fine, can I assume that if I used Windows Media Center that I would have the same result or does performace/capability vary widely between media centres (and i am not talking about the ability to play different formats)?. If someone has the comparison between Twonky and WHM then this would be very handy. The answer to this will depend on what NAS I go for. Whilst we are on the subject, can someone reccomned a NAS?. I am looking for a very fast machine with upto 6TB storage, quiet and very very userfriendly GUI. Thanks again! (especially the suggestion to try streaing from the media centre)