Unsmooth MKV playback on my LCD TV

[Blahpwap]

I've been trying to play about two dozen MKV files on my new Samsung LCD TV (which supports MKV from a USB drive).

Most of the files are supported, but the playback generally isn't smooth, and some files don't even load up.

I have been able to play maybe a couple files completely smoothly, however.

I am trying to figure out what the difference is between the files that play perfectly and the ones that either don't load or play poorly.

Can anyone tell what the problem is and how I should go about trying to 'fix' the MKVs (by re-encoding or otherwise)?

[jman98]

I wish the idiot TV manufacturers had never added the ability to play files to some TV models as all it has done is create unrealistic expectations on the part of consumers that they have a free "plays anything" device in their TV. As you learned the reality is quite far from that.

Use a program like MediaInfo to get as much information as possible about your videos and post the output here from a file that plays fine and from one that is problematic.

[Blahpwap]

Thanks for answering jman98.

I ran MediaInfo on two files that played fine off the USB and one that ran but played poorly.
One is actually a TS file that I once converted from MKV. Of course, I thought maybe that's the solution and tried converting a couple other MKVs to TS but that didn't work as well.
Anyway, the info is:

TS file:

Video
ID : 4113 (0x1011)
Menu ID : 1 (0x1)
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 5 frames
Codec ID : 27
Duration : 1h 47mn
Bit rate mode : Variable
Bit rate : 4 290 Kbps
Maximum bit rate : 40.0 Mbps
Width : 1 280 pixels
Height : 688 pixels
Display aspect ratio : 1.860
Frame rate : 25.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.195
Stream size : 3.26 GiB (70%)
Writing library : x264 core 93 r1542 5b86182
Encoding settings : cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=12 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / wpredb=1 / wpredp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=2pass / mbtree=1 / bitrate=4290 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:1.0
Language : English

Audio
ID : 4352 (0x1100)
Menu ID : 1 (0x1)
Format : DTS
Format/Info : Digital Theater Systems
Codec ID : 130
Duration : 1h 47mn
Bit rate mode : Constant
Bit rate : 1 510 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 24 bits
Compression mode : Lossy
Stream size : 1.14 GiB (25%)
Language : English




And this is a MKV that also seemed to be playing alright:

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 9 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 1h 24mn
Bit rate : 5 152 Kbps
Width : 1 280 pixels
Height : 692 pixels
Display aspect ratio : 1.850
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.243
Stream size : 3.04 GiB (75%)
Title : *
Writing library : x264 core 112 r1867 22bfd31
Encoding settings : cabac=1 / ref=9 / deblock=1:-3:-3 / analyse=0x3:0x133 / me=umh / subme=10 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=48 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=12 / sliced_threads=0 / nr=0 / decimate=0 / interlaced=0 / constrained_intra=0 / bframes=9 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=23 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=0 / crf=17.5 / qcomp=0.60 / qpmin=0 / qpmax=51 / qpstep=4 / vbv_maxrate=50000 / vbv_bufsize=62500 / crf_max=0.0 / nal_hrd=none / ip_ratio=1.40 / pb_ratio=1.30 / aq=1:0.70
Language : English
Color primaries : BT.709-5, BT.1361, IEC 61966-2-4, SMPTE RP177
Transfer characteristics : BT.709-5, BT.1361
Matrix coefficients : BT.709-5, BT.1361, IEC 61966-2-4 709, SMPTE RP177

Audio #1
ID : 2
Format : DTS
Format/Info : Digital Theater Systems
Codec ID : A_DTS
Duration : 1h 24mn
Bit rate mode : Constant
Bit rate : 1 510 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 24 bits
Compression mode : Lossy
Stream size : 913 MiB (22%)
Title : DTS 5.1 1.5 Mbps
Language : English

Audio #2
ID : 3
Format : Vorbis
Format settings, Floor : 1
Codec ID : A_VORBIS
Duration : 1h 24mn
Bit rate mode : Variable
Bit rate : 80.0 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 48.4 MiB (1%)
Title : Commentary Vorbis 2.0 80 kbps
Writing library : aoTuV b5d (UTC 2009-03-01)
Language : English

Text
ID : 4
Format : UTF-8
Codec ID : S_TEXT/UTF8
Codec ID/Info : UTF-8 Plain Text
Language : English


This one didn't play well (worked but not smooth):

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 9 frames
Format settings, GOP : M=1, N=57
Codec ID : V_MPEG4/ISO/AVC
Duration : 1h 44mn
Bit rate : 7 411 Kbps
Width : 1 280 pixels
Height : 694 pixels
Display aspect ratio : 16:9
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.348
Stream size : 5.31 GiB (81%)
Title : *
Writing library : x264 core 102 r1666 d058f37
Encoding settings : cabac=1 / ref=9 / deblock=1:-3:-3 / analyse=0x3:0x113 / me=umh / subme=10 / psy=1 / psy_rd=1.05:0.10 / mixed_ref=1 / me_range=32 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=2 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=6 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / constrained_intra=0 / bframes=6 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=2pass / mbtree=1 / bitrate=7411 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv_maxrate=50000 / vbv_bufsize=50000 / ip_ratio=1.40 / aq=1:0.80 / nal_hrd=none
Language : English

Audio
ID : 2
Format : DTS
Format/Info : Digital Theater Systems
Codec ID : A_DTS
Duration : 1h 44mn
Bit rate mode : Constant
Bit rate : 1 510 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 24 bits
Compression mode : Lossy
Stream size : 1.11 GiB (17%)
Title : *
Language : English

[rumplestiltskin]

Rough guess: Lose the CABAC, drop the bitrate. Other than that, buy a WDTV Media Player for $60 and play most anything.

[guns1inger]

My brother and my folks have Samsungs with the built in media player. It always struggles and chokes on '720p' mkv files. No problems at all with lower resolutions but the same settings. You could try re-encoding the audio to AC3 or AAC instead of DTS, but ultimately you are better off getting a WDTV and leaving the files alone. The built-in player is adequate for basic formats, and rubbish for anything beyond that.

[Megahurts]

I noticed your 1st MediaInfo report is 25fps.

If I play 25fps files (mkv, mpg, vob) through an LG Blu-ray player to an LG 120hz display it plays back jerky about once every second. Doesn't matter if tru-motion is off or on.

Same player connected to a 60hz display, plays back smooth.

Same results when streaming Netflix 25fps movies.

If don't know if it's an LG 120hz problem or all 120hz displays. Is your Samsung 120hz?

[jagabo]

I suspect the TV is having problems with 9 reference frames and 6 b frames. Note that just because the video was encoded with those settings doesn't mean the encoder uses them often. But the properties of individual videos could lead to one using more than the other.

[Blahpwap]

I noticed your 1st MediaInfo report is 25fps.

If I play 25fps files (mkv, mpg, vob) through an LG Blu-ray player to an LG 120hz display it plays back jerky about once every second. Doesn't matter if tru-motion is off or on.

Same player connected to a 60hz display, plays back smooth.

Same results when streaming Netflix 25fps movies.

If don't know if it's an LG 120hz problem or all 120hz displays. Is your Samsung 120hz?

Thanks for replying. Nope, it's a 50hz display.

[Blahpwap]

My brother and my folks have Samsungs with the built in media player. It always struggles and chokes on '720p' mkv files. No problems at all with lower resolutions but the same settings. You could try re-encoding the audio to AC3 or AAC instead of DTS, but ultimately you are better off getting a WDTV and leaving the files alone. The built-in player is adequate for basic formats, and rubbish for anything beyond that.

Thanks for replying.
I wish I had known this before buying the TV, but I actually read on some forums that many people were happy with its built-in player.
Anyway, I tried running AC3 files as well and even converting the files with the DTS to AC3 but it's the same result.
Getting a WDTV would mean I'd have to always convert from DTS to AC3 right? I am considering getting an AC Ryan PlayOn!HD ACR-PV73100...

[Blahpwap]

I suspect the TV is having problems with 9 reference frames and 6 b frames. Note that just because the video was encoded with those settings doesn't mean the encoder uses them often. But the properties of individual videos could lead to one using more than the other.

Thanks for the reply.
Is there a quick way of doing or that to test if it solves the problem or would that mean having to transcode and wait hours on each file?

[jagabo]

I would take one of the videos that's causing problems and reencode a problematic section with similar settings (9 re-frames, 6 b-frames) and with more limited settings (say, 3 re-frames and 2 b-frames). Then see how the TV plays both files. If you use x264 directly you can see how often it used those features. For example the b-frame report for the 6 b-frame encoding will show 6 numbers like "30, 40, 20, 7, 2, 1". That means 30 percent of the time it used 1 b-frame, 40 percent of the time it used 2 b-frames, 20 percent of the time it used 3 b-frames, 7 percent of the time it used 4 b-frames, etc.

Of course, since you're re-encoding the video there's no guarantee it will be encoded with similar numbers of re-frames and b-frames.

If this is the problem, the only way to fix it is to re-encode. Or use a better playback device.

[jman98]

Thanks for replying.
I wish I had known this before buying the TV, but I actually read on some forums that many people were happy with its built-in player.
Anyway, I tried running AC3 files as well and even converting the files with the DTS to AC3 but it's the same result.
Getting a WDTV would mean I'd have to always convert from DTS to AC3 right? I am considering getting an AC Ryan PlayOn!HD ACR-PV73100...

No, the WDTV supports DTS just fine. However, it passes it out in what some call "bitstream mode" which means that you need a receiver to accept the audio input that is capable of decoding DTS. The WDTV itself cannot decode DTS. I am shocked that your TV can apparently decode DTS. I think every TV media player I've ever heard of wouldn't play DTS at all. We get a lot of people posting here asking how to convert DTS to AC3 for that very reason.

The point of getting a WDTV or similar player is that you don't have to convert ANYTHING. You just put your files on some kind of USB device (I use flash drives) and attach it to the WDTV and off you go. One of the newer WDTV models does have an internal disk drive and I believe that all fo the current models can attach to your wireless network so streaming from your PC is possible. Just note that many have reported that 1080 videos don't stream very well so you may need to use USB devices for those.

[Blahpwap]

Thanks for replying.
I wish I had known this before buying the TV, but I actually read on some forums that many people were happy with its built-in player.
Anyway, I tried running AC3 files as well and even converting the files with the DTS to AC3 but it's the same result.
Getting a WDTV would mean I'd have to always convert from DTS to AC3 right? I am considering getting an AC Ryan PlayOn!HD ACR-PV73100...

No, the WDTV supports DTS just fine. However, it passes it out in what some call "bitstream mode" which means that you need a receiver to accept the audio input that is capable of decoding DTS. The WDTV itself cannot decode DTS. I am shocked that your TV can apparently decode DTS. I think every TV media player I've ever heard of wouldn't play DTS at all. We get a lot of people posting here asking how to convert DTS to AC3 for that very reason.

The point of getting a WDTV or similar player is that you don't have to convert ANYTHING. You just put your files on some kind of USB device (I use flash drives) and attach it to the WDTV and off you go. One of the newer WDTV models does have an internal disk drive and I believe that all fo the current models can attach to your wireless network so streaming from your PC is possible. Just note that many have reported that 1080 videos don't stream very well so you may need to use USB devices for those.

Thanks jman98.

I actually bought this TV because I knew it could play MKV files and supports DTS... so figured I wouldn't need a streamer at all. Now it makes no difference.

I'm not sure what you mean by needing to have a receiver to accept the audio input with the WD?

Anyway, I think I'll be going for the AC Ryan streamer I mentioned as I read that it plays just about everything and does DTS downmixing.

[Blahpwap]

I just tried to play a 300MB AVI xvid file and it plays choppy as well.
So apparently this isn't just an mkv issue.
I tried playing the same file off a WD HDD (with speeds up to 25mb/s) and an 8GB flash drive (with speeds up to 6mb/s)... same result :/

[Blahpwap]

After comparing playback from the USB drive on the new LCD TV and playback on an old LCD TV connected to an HTPC, there is one thing that pops up in difference.

Videos played on the new TV seem to skip between frames in a way that looks obvious and unsmooth, while the old TV (connected to a computer) interlaces the picture thus making it look more smooth and natural.

I'm not sure I'm able to explain my meaning so well, does anyone understand what I mean?

[jagabo]

I don't know what you mean. If you have a 100 Hz TV try disabling the motion smoothing. That can get confused at times.

[Blahpwap]

It's a 50 Hz TV.

[jagabo]

What model is it?

[Blahpwap]

Samsung LA37C530

[jagabo]

Yes, it that's a 50 Hz TV with no motion smoothing.

All I can do is suggest you try encoding your own videos with different settings until you find out what the TV's limitations are. Then reencode the videos that don't play with compatible settings. x264 in "veryfast" CRF mode is pretty fast for h.264 encoding.

There's a Divx test cd if you can find it:
http://divxtest.surdvd.com/sommaire.php3?lang=en
I think all the links at that site are dead though. It CD ISO image contains Divx/Xvid videos encoded with a range of different settings. I haven't seen anything like it for h.264 videos.

There are some h.264 bitrate test files here:
http://www.networkedmediatank.com/showthread.php?tid=27616

[Blahpwap]

Would this mean I'd get the same results from a streamer?

[jagabo]

It depends on exactly what you are seeing. Is it worse than movies normally look on TV? Those would be 25 fps on PAL TV (displayed as 50 fields per second but only 25 motion samples per second) and is noticeably jerky if you are very picky. Live sports, at 50 fields (and motion samples) per second, is smoother. If you are seeing something worse than normal 25 fps movies then yes, a streamer will give you better results.

[Blahpwap]

The picture is a LOT more jerky than when I watch TV channels.
But I'm unsure how to technically identify the exact problem... judder? stutter? frame dropping?

[jagabo]

Is it consistent throughout a video or only on some shots? If it's only occasionally it's probably something like too many re-frames or b-frames, or too high a bitrate.

[Blahpwap]

Hard to say. It's pretty consistent but here and there it looks like it's making more of an effort.

[poisondeathray]

Buy why would he have difficulty playing an xvid/avi file - he said that played "choppy" as well?

There's something else going on here, or he's not describing the probelm properly

What happens if you connect the HTPC to the new TV ?

[Blahpwap]

Thanks for replying, poisondeathray.

If I connect my HTPC, there seems to be a slight improvement there but it still isn't smooth.

I would just concede that it's the TV here if it weren't for a couple of files that played flawlessly. one mkv and one ts. that's what doesn't make sense to me.

[poisondeathray]

But if you connect the same HTPC to a different monitor or TV, using the same test file, it plays smoothly ? (i.e. the HTPC and playback software is working properly) ?

[Blahpwap]

Yeah, it does.
I have my HTPC connected to an old Toshiba Regza 32" screen and motion is flawless on it.
I do notice one difference between the TVs though... the older Toshiba LCD TV interlaces the video, and I much prefer it that way.

[poisondeathray]

clarify what you mean by "interlaces the video"

All the mediainfo samples you posted suggest the material you are watching is progressive, not interlaced.



The Toshiba is an LCD or flat panel , correct ? earlier you said it was an "old LCD" . Just want to be clear that it's not a CRT