*Every* video vertically-stretched!

[Astrix8]

EDIT: see update further down the page.

----

I've done a lot of searching throughout the forum, but I haven't found any specific information about fixing aspect ratio problems with MP4 files. Could someone be kind enough to share their knowledge?

All of my MP4 files are vertically stretched even with Zoom set on Actual Size. What sort of information do you need from me about the file in order to diagnose the problem?

I read something on doom9 about putting the MP4 in an mkv and adding --engage keep_bitstream_ar_info to the command-line, so I'm about to try that. I'll report back with any results.

Thanks!

[Astrix8]

The mkvmerge trick didn't work.

What's funny is that some mp4's play no problem, and some don't. I assume it comes down to what version codec was used. I wish someone could steer me in the right direction because I've been hunting all over the place for the answer and I've found nothing. :?

EDIT:

When I load one of my MP4 files into DS Mux, I get this:

avc1 720x426, DAR: 512x213

Could the problem be that the dimensions and the Display Aspect Ratio are different?

[EPiPHON3]

Astrix8 Wrote:The mkvmerge trick didn't work.

What's funny is that some mp4's play no problem, and some don't. I assume it comes down to what version codec was used. I wish someone could steer me in the right direction because I've been hunting all over the place for the answer and I've found nothing. :?

EDIT:

When I load one of my MP4 files into DS Mux, I get this:

avc1 720x426, DAR: 512x213

Could the problem be that the dimensions and the Display Aspect Ratio are different?

Have you tried demuxing -> remux to TS? Or you could just put that MKV you made through tsMuxeR. See what that gives you.

[hangman]

You could try remuxing with mp4box/yamb and changing the AR info.

[Astrix8]

Thanks for the suggestions, guys. I'm going to try both after work tonight.

[spawn]

Astrix8 Wrote:EDIT:

When I load one of my MP4 files into DS Mux, I get this:

avc1 720x426, DAR: 512x213

Could the problem be that the dimensions and the Display Aspect Ratio are different?

Yes - the DAR has an aspect ratio of 2.4 and the encoding is aspect ratio 1.6

Its a socalled anamorphic encoding using non square pixels.
To fit correctly it would normally have been resized and encoded as 720x300 using square pixels. But in order to keep as much quality as possible (I guess) its been encoded using full vertical resolution of 426 lines with non square pixels. Nothing wrong with doing that qualitywise but not all decoders handle anamorphic encodings with nonsquare pixels correct - mostly because the standards and support for handling this varies between container types. And the PCH do have some problems with handling this in certain containers.

I think your best bet is remuxing the .mkv to .ts as EPiPHON3 suggested.

If you are encoding these yourself - you might want to ensure using square pixel encoding only untill Syabas finds a way to handle AR of non square pixel encodings for all containers.

[Astrix8]

Seriously, thanks for all the help. This is a great community and I feel a lot more confident buying Popcorn Hour knowing I can probably find the answer to anything here.

Interesting development. tsMuxer can't detect the stream type and won't let me load the mp4, but I can load an mp4 that my PH plays perfectly.

Aside from being stretched, this movie also plays without sound, despite the audio being mp3. Could it be that the mp4 has multiple audio streams?

Here are the stats I received from MediaInfo on the problem file :

Code:

General #0
Count                        : 196
Count of stream of this kind : 1
Kind of stream               : General
StreamKindID                 : 0
Count of video streams       : 1
Count of audio streams       : 2
Count of text streams        : 2
Count of chapter streams     : 1
Codecs Video                 : MPEG-4 Visual
Audio codecs                 : MPEG-1 Audio / MPEG-1 Audio
Audio_Language_List          : English / French
Text codecs                  : VobSub / VobSub
Text_Language_List           : English / French
Complete name                : C:\Program Files\MediaInfo\TEST.mp4
Folder name                  : C:\Program Files\MediaInfo
File name                    : TEST
File extension               : mp4
Format                       : mp42
Format                       : MPEG-4
Format/Info                  : ISO 14496-1 version 2
Format/Family                : MPEG-4
Format/Url                   : http://www.apple.com/quicktime/download/standalon
e.html
Format/                      : mp4
Codec                        : mp42
Codec                        : MPEG-4
Codec/Info                   : ISO 14496-1 version 2
Codec/Family                 : MPEG-4
Codec/Url                    : http://www.apple.com/quicktime/download/standalon
e.html
Codec/                       : mp4
File size                    : 2588002543
File size                    : 2.41 GiB
File size                    : 2 GiB
File size                    : 2.4 GiB
File size                    : 2.41 GiB
File size                    : 2.410 GiB
PlayTime                     : 6636648
PlayTime                     : 1h 50mn
PlayTime                     : 1h 50mn 36s 648ms
PlayTime                     : 1h 50mn
PlayTime                     : 01:50:36.648
Bit rate                     : 3119650
Bit rate                     : 3120 Kbps
StreamSize                   : 13936564
StreamSize/String            : 13.3 MiB
StreamSize/String1           : 13 MiB
StreamSize/String2           : 13 MiB
StreamSize/String3           : 13.3 MiB
StreamSize/String4           : 13.29 MiB
Encoded date                 : UTC 2007-12-24 11:05:28
Tagged date                  : UTC 2007-12-24 14:16:38
File creation date           : UTC 2008-04-29 01:52:25.859
File last modification date  : UTC 2007-12-24 22:16:39.781

Video #0
Count                        : 90
Count of stream of this kind : 1
Kind of stream               : Video
StreamKindID                 : 0
ID                           : 2
Codec                        : MPEG-4V
Codec                        : MPEG-4 Visual
Codec/Family                 : MPEG-4V
Codec/                       : 20
PlayTime                     : 6636600
PlayTime                     : 1h 50mn
PlayTime                     : 1h 50mn 36s 600ms
PlayTime                     : 1h 50mn
PlayTime                     : 01:50:36.600
Bit rate mode                : VBR
Bit rate                     : 2457032
Bit rate                     : 2457 Kbps
Maximum bit rate             : 5684872
Maximum bit rate             : 5685 Kbps
Width                        : 720
Width                        : 720 pixels
Height                       : 440
Height                       : 440 pixels
Display Aspect ratio         : 1.636
Display Aspect ratio         : 1.636
Frame rate mode              : CFR
Frame rate                   : 25.000
Frame rate                   : 25.000 fps
FrameCount                   : 165915
Bits/(Pixel*Frame)           : 0.310
StreamSize                   : 2038293989
StreamSize/String            : 1.90 GiB
StreamSize/String1           : 2 GiB
StreamSize/String2           : 1.9 GiB
StreamSize/String3           : 1.90 GiB
StreamSize/String4           : 1.898 GiB
Encoded date                 : UTC 2007-12-24 11:05:37
Tagged date                  : UTC 2007-12-24 14:16:38

Audio #0
Count                        : 75
Count of stream of this kind : 2
Kind of stream               : Audio
StreamKindID                 : 0
ID                           : 3
Codec                        : MPEG-1A
Codec                        : MPEG-1 Audio
Codec/Family                 : MPEG-A
Codec/                       : 6B
PlayTime                     : 6636648
PlayTime                     : 1h 50mn
PlayTime                     : 1h 50mn 36s 648ms
PlayTime                     : 1h 50mn
PlayTime                     : 01:50:36.648
Bit rate mode                : VBR
Bit rate                     : 320000
Bit rate                     : 320 Kbps
Maximum bit rate             : 330240
Maximum bit rate             : 330 Kbps
Channel(s)                   : 2
Channel(s)                   : 2 channels
Sampling rate                : 48000
Sampling rate                : 48.0 KHz
SamplingCount                : 318559104
Resolution                   : 16
Resolution                   : 16 bits
StreamSize                   : 265465920
StreamSize/String            : 253 MiB
StreamSize/String1           : 253 MiB
StreamSize/String2           : 253 MiB
StreamSize/String3           : 253 MiB
StreamSize/String4           : 253.2 MiB
Title                        : English
Language                     : en
Language                     : English
Encoded date                 : UTC 2007-12-24 11:05:37
Tagged date                  : UTC 2007-12-24 14:16:38

Audio #1
Count                        : 75
Count of stream of this kind : 2
Kind of stream               : Audio
StreamKindID                 : 1
ID                           : 4
Codec                        : MPEG-1A
Codec                        : MPEG-1 Audio
Codec/Family                 : MPEG-A
Codec/                       : 6B
PlayTime                     : 6636600
PlayTime                     : 1h 50mn
PlayTime                     : 1h 50mn 36s 600ms
PlayTime                     : 1h 50mn
PlayTime                     : 01:50:36.600
Bit rate mode                : VBR
Bit rate                     : 320000
Bit rate                     : 320 Kbps
Maximum bit rate             : 330240
Maximum bit rate             : 330 Kbps
Channel(s)                   : 2
Channel(s)                   : 2 channels
Sampling rate                : 48000
Sampling rate                : 48.0 KHz
SamplingCount                : 318556800
Resolution                   : 16
Resolution                   : 16 bits
StreamSize                   : 265464000
StreamSize/String            : 253 MiB
StreamSize/String1           : 253 MiB
StreamSize/String2           : 253 MiB
StreamSize/String3           : 253 MiB
StreamSize/String4           : 253.2 MiB
Title                        : French
Language                     : fr
Language                     : French
Encoded date                 : UTC 2007-12-24 11:05:37
Tagged date                  : UTC 2007-12-24 14:16:38

I'm not too familiar with command line but I can fake it. I had to copy the file into the same directory as mediainfo.exe in order to run 'mediainfo TEST.mp4 -f'. Can I, or how would I, format the string to target a file in a different directory? The string 'mediainfo F:\My Movies\TEST.mp4' doesn't work.

On a side note, can anyone tell me why a 0 KB "TEST.mp4" reappears even after I delete the original file? If I delete this empty file, it pops up a second later and persists until I empty my rec bin. :?

EDIT:

I used YAMB to extract the video and first audio stream from TEST.mp4 and got an mp4 file and an mp3 file. YAMB and Haali's DS Mux recognize the mp4 file, while mkvmerge and tsMuxeR will not. The resultant mkv plays fine in Media Player Classic, but mkvextract and txMuxeR refuse to see the video stream.

So, it's the video, isn't it? But what? Is it the DAR vs. the PAR? (Wow, I've learned a lot about this stuff in two days. Had you asked me on Friday what DAR stands for, I would've guessed Democrats And Republicans.) Is there some way to fix the mp4 file without re-encoding from source?

[Astrix8]

Well, after two nights, still no luck determining the problem with my mp4's. I can't even remux to .ts because txMuxeR will not accept the video stream.

I'll keep working on it, and update this thread if I find a solution. Thanks for everyone's advice!

[Astrix8]

bump in case someone can make sense if the specs I posted and explain why the mp4 won't play at the right AR.

[Astrix8]

This is CRAZY! :shock:

I've taken the time to sit with my Popcorn Hour hooked up to a 4:3 lcd and my external hd with the same movies hooked up to my 16:9 lcd. I've synced up every movie on both drives and I've noticed a strange phenomenon. Every video, and I mean every video, playing on my 4:3 TV or 4:3 lcd monitor is stretched vertically by2–20%. The same files on my hard drive playing through Media Player Classic are just fine.

I thought at first it was just my mp4's, but it's every single video, even 4:3 content, which is actually squeezed in at the sides. For the majority of the files, it's not enough to notice if you're not looking for it, but it's there, and now that I've compared the two, it's impossible to watch a movie on my PH without seeing it.

I consider this to be a major issue. I can't believe every video, encoded by countless different individuals, could all have the same basic aspect ratio problem. I've opened up a case on the support site, but I'm wondering if anyone else can verify the same aspect ratio problem on 4:3 televisions.

[n8gray]

I'm pretty sure "incorrect aspect ration on 4x3 displays" is a known issue in the current firmware. Bugs me too. :/

[chris57]

Yes it is and the firmware team are working furiously to solve it. The latest betas solve it for 16:9 NTSC on a 4:3 display but PAL still has to be fixed. Hopefully both will be in time for the next stable.

Syabas are also rethinking the whole aspect ratio:

Hi guys, thanks for the feedback.

Yes, indeed Aspect Ratio issue has always been a problem, compounded by the "Full Screen, Fit-to-screen and Actual Size" scaling.

Therefore, after much internal discussion, we have decided to implement the following....

"TV Type" setting will be moved from DVD to Audio/Video settings and will apply to all playback (including DVD).
This will have 4:3 Letterbox, 4:3 Pan Scan, 16:9 setting
This will determine how the video will be shown on the TV.

As for aspect ratio, we will follow the DAR (display aspect ratio) information from the clip. Currently there is no function to override the aspect ratio in case it is wrong in the clip.

Meanwhile, we will still provide "Full-screen" and "Actual Size" scaling under Zoom, and in future, a progressive Zoom as well.

"Full-screen" will just try to fill the whole TV with video, irregardless of Aspect Ratio, to eliminate the black borders.

"Actual Size" will be useful when watching low-res videos, like YouTube in its actual resolution.

So in summary you are not going crazy but the problem is being worked on with prioroty.

[Astrix8]

Thanks for the great response, chris! Glad to know I'm not losing it!