incorrect aspect ratio with mkv's, everything else fine.

[a_dude]

I've dealt with literally hundreds of files in varying codecs and vlc has been a dream come true for the compatibility hungry mac user, but for some reason MKV files have been displaying with improper aspect ratios.

The files themselves are Xvid with dual aac audio and both SRT and SSA format tracks embedded. While I might normally consider this an xvid problem, I often get varying containers with the same build of xvid used, and the avi containers display fine.

I run vlc 0.8.1 (sorry no build # on the info) for macos X (the downloadable binary) and am running a dual ppc g4 with os X.4.0 (tiger as sold on release day)

I'll attach a picture comparing VLC to mplayer to give you the general idea of what i'm talking about.. the distortion seems to be the same across all vids with the aspect ratio imaged here.

[Alexsource]

I would dare to say that vlc is showing the video stream at it's actual size/ratio, but the mkv has an aspect ratio tag setted that vlc is ignoring, while mplayer isn't, and so, it's playing the video at the correct taged inside the mkv ratio, alltought the video was ripped out of ratio (i've heard some DVDs are like this... they say it's 16:9, but it's actually 4:3 without pan-scan, i guess it's something to do with 16:9 tvs getting a wide popularity or something).
You'll have to extract the video stream from the mkv to be sure, google for mkv toolnix or some other mkv muxers/demuxers.

[Guest]

The one hole in your theory about the sizes is that if it were true there wouldn't be the stretching-type distortion which is occuring in the vid capture i posted. notice how the eyelid is severely stretched.

Unfortunately mkvdemux stopped working for macos X.4 so i can't confirm/deny that for you or any dev's perusing the forum, but I do have the output from the mkvinfo tool.
I don't know if the information spat out is stored within the track or within the mkv container params (BECAUSE i can't extract the track), but I do know the parameter being ignored is "Display width:" and "Display height:"

The "Pixel width" and "Pixel height" are being used alone.. resulting in the stretching.

The mkvinfo results for the mkv header and video track using mkvtoolnix 1.4.2

plasmacutter$ ./mkvinfo /Users/plasmacutter/XXXXX.mkv
+ EBML head
+ Segment, size 358178491
|+ Seek head (subentries will be skipped)
|+ EbmlVoid (size: 3996)
|+ Segment information
| + Timecode scale: 1000000
| + Muxing application: libebml v0.7.3 + libmatroska v0.7.4
| + Writing application: mkvmerge v1.0 ('Soul Food To Go') built on Nov 17 2004 15:06:35
| + Duration: 1502.102s (00:25:02.102000000)
| + Date: Thu Jan 27 19:22:30 2005 UTC
| + Segment UID: 0x5a 0x1f 0x2d 0xc2 0xc6 0xdb 0x62 0x89 0x43 0xe0 0x1c 0x4e 0x2d 0x4f 0xcc 0xc1
|+ Segment tracks
| + A track
| + Track number: 1
| + Track UID: 531913456
| + Track type: video
| + Default flag: 1
| + Lacing flag: 0
| + MinCache: 1
| + Timecode scale: 1.000000
| + Codec ID: V_MS/VFW/FOURCC
| + CodecPrivate, length 40 (FourCC: XVID, 0x44495658)
| + Default duration: 41.708ms (23.976 fps for a video track)
| + Language: und
| + Name: XXXXXXXXXXXXXXX
| + Video track
| + Pixel width: 704 //These pixel params are applied alone.
| + Pixel height: 480
| + Display width: 853 // These "Display" params are being ignored.
| + Display height: 480
| + A track

[a_dude]

it seems the latest build has fixed this issue... i saw a link in another thread.

[gullevek]

OS: Mac OS X 10.4
VLC: 0.8.1

I have the same problem. I also use Tiger and the display size gets ignored.

I could swear that with 10.3 it was correct. But of course I could be wrong.

[robUx4]

As said, it's fixed in nightly builds. But matroska is disabled in the very latest nightly builds because of some bugs to be solved. So use older nightlies (mid-april)...

[plasmacutter]

actually the latest build (5/05) does work with matroska..

though there are occasionaly random crashes (expected from an alpha), the playback is pretty good when it doesn't crash.

[Guest]

The only aspect ratio problem I've had with VLC for .mkv files (on Panther and Tiger) is trying to display anamorphic files. It always seems to display them wrong. Is this fixed in the latest builds?

On a side note, a_dude can you get the dual AAC audio tracks to play back without problems in the latest builds? I'm assuming they're 5.1 AAC audio tracks, which have had problems with outputting to the proper channels in VLC. Is this fixed?