MKV Doesnt play smoothly

[yoclick]

Hi,

I've got a trailer in an MKV file. Its in HD (720p) and states x264 in the filename? I had never heard of these files before so did some research into finding a codec which would play it, and ended up installing CCCP.

Now the files plays through WMP but is juddering and pausing etc. On VLC its very very smooth but pauses quite a bit. This would normally lead me to think its my laptop which isnt fast enough to process it but its a Intel Core2Duo T5600 (1.83ghz) with 2GB DDR2 RAM? Surely thats enough to play this video, isnt it?

Please help

[directhex]

MKV is a container format (like AVI, MOV, WMV, RM, MPG) called Matroska. It's not relevant to your problem.

H.264 is a family of codecs (MPEG 4 part 10, sometimes called AVC or H.264). It's extremely space efficient compared to MPEG 4 part 2 codecs (DiVX/XViD/3ivx etc), but extremely complex to encode and decode

x264 is an open-source H.264 implementation. The advantage is it's free, the disadvantage is it's very slow, and computers fast enough to decode an HD H.264 stream using x264 are rare (no, your core2 isn't fast enough). there are three other common codec implementations which should manage it though, but you may find yourself parting with cash: CoreAVC, PowerDVD Ultra, Nero Digital, and Quicktime. There are also GPU hardware based options - Nvidia Purevideo HD, or ATI Avivo - you'll need a player which can make use of the GPU back end, and the only one I'm certain does is the (payware) Nero Digital.

[yoclick]

Thanks for the info directhex.

What i intend to do is stream this over to my PS3 via TVersity. So im guessing if my laptop cant properly decode the video, i have no chance of a real-time transcoding? The thing is i didnt realise i had AVG doing a full scan in the background (thing updates everytime i boot my laptop and i forget its always scanning!). Well it finished, and i tried the video through WMP11 and it worked! Only played a minute but it was smooth throughout. However its still playing slow and juddering through TVersity on my laptop.

TVersity is currently using directshow codecs. So if i purchase CoreAVC (for example), what are the chances il receive a smooth picture at my PS3 end? BTW The laptop and PS3 are connected wireless, but in the same room as the router, so both within 4 meters. Signal is 54g. A rough idea would be nice before i have to part cash.

Many Thanks :-)

[mroz]

MKV is a container format (like AVI, MOV, WMV, RM, MPG) called Matroska. It's not relevant to your problem.

H.264 is a family of codecs (MPEG 4 part 10, sometimes called AVC or H.264). It's extremely space efficient compared to MPEG 4 part 2 codecs (DiVX/XViD/3ivx etc), but extremely complex to encode and decode

Agreed.

x264 is an open-source H.264 implementation. The advantage is it's free, the disadvantage is it's very slow, and computers fast enough to decode an HD H.264 stream using x264 are rare]

Wrong, irrelevant & misleading - nice to be thorough, isn't it

x264 is a free open-source h.264 encoder. As you say previously, h.264 is computationally very heavy to both encode & decode. However the x264 implementation is actually very fast & efficient as h.264 goes.

That said, its speed & efficiency at encoding are irrelevant to the time taken to decode. That depends purely on the decoder & which h.264 features have been used in the encoding (as with most codecs, there are many parameters controlling how the video is encoded; most trade speed for quality, though depending on the feature this might affect only encoding speed, only decoding speed or sometimes both).

So, what the OP needs to know is is there a decoder which can handle 720p h.264 for his hardware. My guess would be that it may well, but only with a decoder that uses both cores to do the decoding. CCCP seems to be a filter pack; a quick check suggests it uses ffdshow. I personally love ffdshow, but I'm pretty sure its h.264 decoding isn't multithreaded. Certainly it isn't the fastest of decoders.

(no, your core2 isn't fast enough). there are three other common codec implementations which should manage it though, but you may find yourself parting with cash: CoreAVC, PowerDVD Ultra, Nero Digital, and Quicktime.

CoreAVC is rather nice, probably the fastest decoder & will use both cores. I'd say it's well worth a shot. I've no experience of PowerDVD for h.264. Nero Digital is faster than fdshow, but i'd prefer CoreAVC if you can get the company to sell you a copy (they seemed to be having some issues with customer support). Quicktime I wouldn't touch with a barge poll, other than possibly to try to push it under the surface & drown the forever.

[mroz]

Thanks for the info directhex.

What i intend to do is stream this over to my PS3 via TVersity. So im guessing if my laptop cant properly decode the video, i have no chance of a real-time transcoding? The thing is i didnt realise i had AVG doing a full scan in the background (thing updates everytime i boot my laptop and i forget its always scanning!). Well it finished, and i tried the video through WMP11 and it worked! Only played a minute but it was smooth throughout. However its still playing slow and juddering through TVersity on my laptop.

TVersity is currently using directshow codecs. So if i purchase CoreAVC (for example), what are the chances il receive a smooth picture at my PS3 end? BTW The laptop and PS3 are connected wireless, but in the same room as the router, so both within 4 meters. Signal is 54g. A rough idea would be nice before i have to part cash.

Many Thanks :-)

Ah, this is a totally different problem. The PS3 will happily handle h.264 720p natively. You don't want to go transcoding it; waste of time, effort & quality. TVersity might still be an option, but only when it supports real time remuxing, which last time I checked it didn't (it was on their list for future implementation).

The PS3 however won't play, aiui, mkvs & is picky about the header info in an mp4. What you need to do is remux the mkv into an mp4 container that the PS3 will be happy with. Try Google, though it means more reading.

[yoclick]

Brilliant mroz

I shall report back asap!

[yoclick]

Ok, back with more info.

I used GOTSent to demux my file and now i have it in mp4 format. I sent the file over via TVersity with no transcoding and it worked! PS3 opened the file with no problem and started playing it. However here is the odd stuff....

Its just as jerky as before? Although its not transcoding, the vid is just as jerky as before with the original mkv file being transcoded?

I turned on the transcoding function yet again on TVersity and this time, selected the box which lowers the bitrate of the output if its too high for my network. I then also reported to it that im using a Poor 11B signal when im actually using an Excellent 54g signal. Well jerkiness dramtically decreased but not fully or to a degree i could watch.

What should i do now?
I could cable my laptop directly to the PS3 easily, but will that make a difference? I thought i would need the laptop and PS3 wired to the router to see a difference, not connected together?

Please guide me to next steps

[yoclick]

Actually i think theres two problems, my network AND CPU! lol

Ok so here we go:
MKV file via TVersity transcoding = Juddering
MKV file via TVersity transcoding w/ output bitrate being decreased = Less Juddering
MP4 file via TVersity NO transcoding = Juddering
MP4 file via TVersity transcoding w/ output bitrate being decreased = Much less juddering

Hmm! I dont understand why there is less juddering when an MP4 file is being transcoded then when an MKV file is? Is it less CPU intensive?
How do i go about connecting the laptop to the PS3 wired? Just to diagnose if its network or CPU problem.

[jimmyjimmyo]

If you want to connect your laptop to your PS3 directly then a crossover cable is all you need.

I had similar issues with my pc and the PS3 on a wired network but transcoding the same file to my 360 using transcode360 it was fine and very smooth.

What codecs have you got installed on your PC?

[mroz]

Afraid I can't add any more as I don't have a PS3 yet & you probably need advice on exactly what performance to expect in order to diagnose your problem.

As jimmyjimmyo said, to connect your laptop & PS3 by cable, all you want is a Cat 5 network cable of the type described as crossover (which describes how the cable is wired up), assuming your laptop has a lan port.

To eliminate network problems altogether, can you burn the file to disk & try to play it from there in the PS3?

I'd try posting on some of the PS3 forums. If you can replicate the problem using a short clip cut from the video, you might be able to upload that somewhere & get some other PS3 users to see if they have the same trouble.

Oh, it's also worth making sure the problem isn't with the video itself, which will mean playing it on some hardware you know can handle 720p h.264.

[yoclick]

jimmyjimmyo, i have CCCP codec pack installed on my computer. I tried to connect the PS3 + Laptop with crossover cable but nothing really happened and i still think they were sending the files over my wireless network and not via the cable. Suppose i can turn off my router but that means everytime i want to watch something in HD, il have to turn my router off?

mroz, check my 2nd post. The video is already playing smoothly on my laptop. I honestly think its just my network causing the problems and once i have PS3 and Laptop wired, im sure my problems will go! But thanks a lot to you for getting me this far where the vid is playing on my laptop

[mroz]

I tried to connect the PS3 + Laptop with crossover cable but nothing really happened and i still think they were sending the files over my wireless network and not via the cable. Suppose i can turn off my router but that means everytime i want to watch something in HD, il have to turn my router off?

Can't you just turn off wireless in the PS3? Is there not some way to tell the PS3 to use its lan port rather than wireless? <checks via google> Yes, apparently you have to specify wired/wireless when setting up the PS3 network connectivity.

It's worth trying this to see if wireless is the problem.

If it is, then it becomes a little bit of a pain in practice having to toggle this setting when you want to watch a movie, but as long as the PS3 remembers the wireless settings even when you switch to wired, it shouldn't be too much of a hassle.

It might even be possible to get the PS3 to cope with both connections at once, but i'd not hold out too much hope of this. Worth investigating though.

Edit: Or of course, if it's physically possible, just run a permanent cable from your router to the PS3 & laptop. If you need wireless on the laptop it should be possible to configure it to try to use the cabled interface only for traffic to the PS3 & wireless for everything else. You'd need to look into configuring routing on the laptop (not sure if the router would also need manually configuring in this respect).

Edit2: Isn't networking fun?

[directhex]

it could well be the network bandwidth that's the problem, looking at it - 54mbit wireless with optimal reception is still only about 2/3 as fast as a non-hd dvd would need

as suggested, try loading your movie from a disc?

[mroz]

it could well be the network bandwidth that's the problem, looking at it - 54mbit wireless with optimal reception is still only about 2/3 as fast as a non-hd dvd would need

That can't be right, can it? Assuming, roughly, a 7.2GB dvd lasts 2 hours, which is generous, that's 8Mb/s, surely, or am I still half asleep?