[UnisonRuss]

There is nothing we can do upgrading hardware wise, unless we all stripped the ATV bare and made our own box...that would be time consuming and costly though. it will have to be the developers that come up with a way to utilize the GPU somehow, or cut down on CPU usage even further through future updates.

[sircube]

well, it's a transcode process so yes, theoretically you lose quality, but you'll still end up with very good quality
another option would be to use a couple of tools to convert mkvs into mp4s without re-encoding, but that's a bit more complicated: http://code.google.com/p/mkvtops3mp4/

here's another tutorial: http://forums.macrumors.com/showthread.php?t=622894

randy.

Further more you can try mkv2vob. Simple interface.

e.g. 8GB MKV with
Resolution : 1280x688
Video Bitrate : 7580 kbps
Audio Specs : Mayan AC3 5.1 @ 640 kbps

can be relative fast converted to vob or other container using "just" mpeg-2 encode (1.5 hours on my dual core T61p). File size grows 10% but disk space normally isn't a problem if you're in the highdef world.
Point is that MPEG-2 requires least processing that's why I go with it. 720p files play smoothly.
I still keep the original mkv hoping for a GPU acceleration some point in time.

[Fede84]

Further more you can try mkv2vob. Simple interface.

e.g. 8GB MKV with
Resolution : 1280x688
Video Bitrate : 7580 kbps
Audio Specs : Mayan AC3 5.1 @ 640 kbps

can be relative fast converted to vob or other container using "just" mpeg-2 encode (1.5 hours on my dual core T61p). File size grows 10% but disk space normally isn't a problem if you're in the highdef world.
Point is that MPEG-2 requires least processing that's why I go with it. 720p files play smoothly.
I still keep the original mkv hoping for a GPU acceleration some point in time.

But in this way i have a loss of quality or not?

[UnisonRuss]

Are you transcoding the video into the VOB or just remuxing? That makes a big difference! If you are transcoding using this program it is the same as encoding the file using Handbrake...but if you are just remuxing and the 720P content is playing smoothly then you are on to something!

...I must do some testing now

[UnisonRuss]

Same playback with the remuxed files as I suspected...I will add however that since the new launcher 720P files are playing back almost flawlessly, just some jitters on pan shots, and dropped frames here and there, definitely a noticeable difference though! Keep up the good work guys, soon ATV will do what we want it to do

[Fede84]

Same playback with the remuxed files as I suspected...I will add however that since the new launcher 720P files are playing back almost flawlessly, just some jitters on pan shots, and dropped frames here and there, definitely a noticeable difference though! Keep up the good work guys, soon ATV will do what we want it to do

Yes, it's true that with the new launcher playng it's a little better.. I've try MKV2VOB with no transcoding and one audio track, this are the result:

MKV:

Code:

*** MediaInfo Mac // Plain text file report
2009-01-22 00:28:39 +0100
Information for File:  Agente Smart - Casino totale.mkv

General / Container Stream # 1
    Total Video Streams for this File -> 1
    Total Audio Streams for this File -> 2
    Video Codecs Used -> AVC
    Audio Codecs Used -> AC3 / AC3
    File Format -> Matroska
    Play Time -> 1h 45mn
    Total File Size -> 4.36 GiB
    Total Stream BitRate -> 5 913 Kbps
    Encoded with -> mkvmerge v2.1.0 ('Another Place To Fall') built on Aug 19 2007 13:40:07
    Encoding Library -> libebml v0.7.7 + libmatroska v0.8.1
Video Stream # 1
    Codec (Human Name) -> AVC
    Codec (FourCC) -> V_MPEG4/ISO/AVC
    Codec Profile -> [email protected]
    Frame Width -> 1 280 pixels
    Frame Height -> 720 pixels
    Frame Rate -> 25.000 fps
    Total Frames -> 158294
    Display Aspect Ratio -> 16/9
    Scan Type -> Progressive
    Colorimetry -> 4:2:0
    Codec Settings (Summary) -> CABAC / 5 Ref Frames
    QF (like Gordian Knot) -> 0.219
    Codec Settings (CABAC) -> Yes
    Video Stream Length -> 1h 45mn 31s 760ms
    Video Stream BitRate -> 5 026 Kbps
    Video Stream BitRate (Nominal) -> 5 045 Kbps
    Bit Depth -> 24 bits
    Video Encoder -> x264 - core 65 r999 cc51047
    Video Encoder (Settings) -> cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x3:0x113 / me=umh / subme=7 / psy_rd=1.0:0.0 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / chroma_qp_offset=-2 / threads=6 / nr=0 / decimate=1 / mbaff=0 / bframes=3 / b_pyramid=1 / b_adapt=1 / b_bias=0 / direct=1 / wpredb=1 / keyint=250 / keyint_min=25 / scenecut=40(pre) / rc=2pass / bitrate=5045 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / pb_ratio=1.30 / aq=1:1.00
    Video Stream Language -> English
Audio Stream # 1
    Codec -> AC-3
    Codec (FourCC) -> A_AC3
    Audio Stream Length -> 1h 45mn 31s 760ms
    Audio Stream BitRate -> 384 Kbps
    Audio Stream BitRate Mode -> CBR
    Number of Audio Channels -> 6
    Audio Channel's Positions -> Front: L C R, Rear: L R, LFE
    Sampling Rate -> 48.0 KHz
    Audio Stream Language -> Italian
Audio Stream # 2
    Codec -> AC-3
    Codec (FourCC) -> A_AC3
    Audio Stream Length -> 1h 45mn 31s 760ms
    Audio Stream BitRate -> 256 Kbps
    Audio Stream BitRate Mode -> CBR
    Number of Audio Channels -> 6
    Audio Channel's Positions -> Front: L C R, Rear: L R, LFE
    Sampling Rate -> 48.0 KHz
    Audio Stream Language -> English

and this isa the MPEG:

Code:

*** MediaInfo Mac // Plain text file report
2009-01-22 00:29:23 +0100
Information for File:  Agente Smart - Casino totale.mpg

General / Container Stream # 1
    Total Video Streams for this File -> 1
    Total Audio Streams for this File -> 1
    Video Codecs Used -> AVC
    Audio Codecs Used -> AC3
    File Format -> MPEG-TS
    Play Time -> 1h 45mn
    Total File Size -> 4.31 GiB
    Total Stream BitRate -> 5 853 Kbps
Video Stream # 1
    Codec (Human Name) -> AVC
    Codec Profile -> [email protected]
    Frame Width -> 1 280 pixels
    Frame Height -> 720 pixels
    Frame Rate -> 25.000 fps
    Total Frames -> 158289
    Display Aspect Ratio -> 16/9
    Scan Type -> Progressive
    Colorimetry -> 4:2:0
    Codec Settings (Summary) -> CABAC / 5 Ref Frames
    QF (like Gordian Knot) -> 0.219
    Codec Settings (CABAC) -> Yes
    Video Stream Length -> 1h 45mn 31s 560ms
    Video Stream BitRate -> 5 237 Kbps
    Video Stream BitRate (Nominal) -> 5 045 Kbps
    Bit Depth -> 24 bits
    Video Encoder -> x264 - core 65 r999 cc51047
    Video Encoder (Settings) -> cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x3:0x113 / me=umh / subme=7 / psy_rd=1.0:0.0 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / chroma_qp_offset=-2 / threads=6 / nr=0 / decimate=1 / mbaff=0 / bframes=3 / b_pyramid=1 / b_adapt=1 / b_bias=0 / direct=1 / wpredb=1 / keyint=250 / keyint_min=25 / scenecut=40(pre) / rc=2pass / bitrate=5045 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / pb_ratio=1.30 / aq=1:1.0
Audio Stream # 1
    Codec -> AC-3
    Audio Stream Length -> 1h 45mn 31s 560ms
    Audio Stream BitRate -> 384 Kbps
    Audio Stream BitRate Mode -> CBR
    Number of Audio Channels -> 6
    Audio Channel's Positions -> Front: L C R, Rear: L R, LFE
    Sampling Rate -> 48.0 KHz
    Audio Stream Delay -> 10mn 0s

I'm not an expert but i thing that the 2 files are equal or i'm wrong?

[UnisonRuss]

Yes, it's true that with the new launcher playng it's a little better.. I've try MKV2VOB with no transcoding and one audio track, this are the result:

MKV:

Code:

*** MediaInfo Mac // Plain text file report
2009-01-22 00:28:39 +0100
Information for File:  Agente Smart - Casino totale.mkv
    
Codec Profile -> [email protected]

and this isa the MPEG:

Code:

*** MediaInfo Mac // Plain text file report
2009-01-22 00:29:23 +0100
Information for File:  Agente Smart - Casino totale.mpg
    
Codec Profile -> [email protected]

I'm not an expert but i thing that the 2 files are equal or i'm wrong?

The level changed; L=Level and 4.1 is High Profile while 3.1 is Main Profile...the higher level the harder it is to playback...theoretically.

My new theory is that it may be the audio stream the file has...AC3 may make it harder to playback smoothly because of extra decoding involved. I have extracted a AC3 stream and muxed the video file and new AAC file into a MP4...I am going to watch it tonight and see how it plays.

[Fede84]

ok, i'll wait your opinion.. if it works you can tell me how i can do that? Thx

[sircube]

Interesting so see that codec profile changes by different muxing to container.

However... I meant another tool for easy re-encoding purpose.
Sorry, miracle is not something for today.
For handling high-bitrate files like in my example I see no other choice than using less resource demanding encode. Reducing the sound channels/encode and therefore complexity might help you with less glitches for files around 5000 Kbps. Lets see.

[Fede84]

The level changed; L=Level and 4.1 is High Profile while 3.1 is Main Profile...the higher level the harder it is to playback...theoretically.

My new theory is that it may be the audio stream the file has...AC3 may make it harder to playback smoothly because of extra decoding involved. I have extracted a AC3 stream and muxed the video file and new AAC file into a MP4...I am going to watch it tonight and see how it plays.

Some new for you theory? i'm intrested in that

[UnisonRuss]

From what I can tell the audio/container has made no big difference...the video plays slightly better with 2.0 audio and an MP4 container, but not good enough to go through all of the trouble. Either we just wait it out for a new launcher that helps the video playback even more and deal with the glitchy video, or encode the 720P content to a smaller resolution/file size and not deal with the glitchy video until we know it's resolved

[Fede84]

A question: It's better i upddate the Apple TV FW at 2.3 or it's better i leave the FW to 2.1?? To have improvment for MKV files.. Thx

[UnisonRuss]

I have only used 2.3 so I have no basis of comparison, but MKV files (for the most part) are playing pretty good since the newest launcher

[nikiiv]

What good the launcher can bring into mkv playback.. just wondering

[UnisonRuss]

I believe it has to do with CPU usage...the less usage with the program the more dedicated to performance...