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MP4 files that skip?

J

JMEANS

macrumors regular
Original poster
Jun 9, 2012
172
5
So I have a few MP4 that for whatever reason when imported into iTunes skip or better description would be stutter along when playing in iTunes and are basically unwatchable : (

The quality of the file is great just doesn't play properly, any known culprit you can think of that would cause suck an issue?

After dropping into 'file info' software the audio looks normal but the video info reads AVC even though the file has the .mp4 extension, that right? Thanks Jim
 
SandboxGeneral

SandboxGeneral

Moderator emeritus
Sep 8, 2010
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Detroit
I assume that the files play just fine in another player before going into iTunes right?

Any change of ripping them again and directly into iTunes?
 
J

JMEANS

macrumors regular
Original poster
Jun 9, 2012
172
5
Yes perfectly fine in VLC. ITunes certainly imports them due to the mp4 container, but somewhere along the line within the file there is a factor that doesn't contain complete mp4/ iTunes compatibility.... Weird

On another note what is AVC video file?
 
SandboxGeneral

SandboxGeneral

Moderator emeritus
Sep 8, 2010
26,482
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Detroit
JMEANS said:
On another note what is AVC video file?
Click to expand...

H.264/MPEG-4 AVC
H.264/MPEG-4 Part 10 or AVC (Advanced Video Coding) is a standard for video compression, and is currently one of the most commonly used formats for the recording, compression, and distribution of high definition video. The final drafting work on the first version of the standard was completed in May 2003.
H.264/MPEG-4 AVC is a block-oriented motion-compensation-based codec standard developed by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC JTC1 Moving Picture Experts Group (MPEG). The project partnership effort is known as the Joint Video Team (JVT). The ITU-T H.264 standard and the ISO/IEC MPEG-4 AVC standard (formally, ISO/IEC 14496-10 – MPEG-4 Part 10, Advanced Video Coding) are jointly maintained so that they have identical technical content.
H.264 is perhaps best known as being one of the codec standards for Blu-ray Discs; all Blu-ray Disc players must be able to decode H.264. It is also widely used by streaming internet sources, such as videos from Vimeo, YouTube, and the iTunes Store, web software such as the Adobe Flash Player and Microsoft Silverlight, and also various HDTV broadcasts over terrestrial (ATSC, ISDB-T, DVB-T or DVB-T2), cable (DVB-C) and satellite (DVB-S and DVB-S2).
Click to expand...
 
J

JMEANS

macrumors regular
Original poster
Jun 9, 2012
172
5
Thanks pretty much what I thought with AVC, however with the file stutter, my best guess is an audio thing, I will run it thru Mp4Tools and add a 2 channel track?
 
M

Mackan

macrumors 65816
Sep 16, 2007
1,421
91
Try play it QuickTime X. The iTunes player has always been horrible for me.
 
M

Menneisyys2

macrumors 603
Jun 7, 2011
5,997
1,101
JMEANS said:
Thanks pretty much what I thought with AVC, however with the file stutter, my best guess is an audio thing, I will run it thru Mp4Tools and add a 2 channel track?
Click to expand...

Can you upload the shortest of them somewhere (e.g., copy.com - it has 20 GB free) so that we take a look?
 
J

JMEANS

macrumors regular
Original poster
Jun 9, 2012
172
5
Menneisyys2 said:
Can you upload the shortest of them somewhere (e.g., copy.com - it has 20 GB free) so that we take a look?
Click to expand...

Thanks for asking, but all i can do is send along this direct info from the file. This is after i ran the .avi file thru MP4Tools adding a 2 channel audio and changing the container to .mv4

Again it plays fine in VLC and can import to iTunes, however when it plays in iTunes it stutters a long...

I have changed containers with many files I haven't Handbreaked myself and have had success, however some are picky like this one. Thanks again for any help you can send my way - Jim


GB2file.jpg
 
Idgit

Idgit

macrumors 6502a
Mar 14, 2004
551
158
JMEANS said:
Thanks for asking, but all i can do is send along this direct info from the file. This is after i ran the .avi file thru MP4Tools adding a 2 channel audio and changing the container to .mv4

Again it plays fine in VLC and can import to iTunes, however when it plays in iTunes it stutters a long...
Click to expand...

Your MP4 does not contain a h.264 video file. It looks like it's an Xvid-encoded Mpeg-4 file. I suspect that is the source of your problem. Transcode it with Handbrake (with audio passthrough).
 
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M

Menneisyys2

macrumors 603
Jun 7, 2011
5,997
1,101
Idgit said:
Your MP4 does not contain a h.264 video file. It looks like it's an Xvid-encoded Mpeg-4 file. I suspect that is the source of your problem. Transcode it with Handbrake (with audio passthrough).
Click to expand...

Yup, it's Xvid, this is why there are problems.
 
J

JMEANS

macrumors regular
Original poster
Jun 9, 2012
172
5
thanks everyone

but crap : ( really didnt want to handbreak (transcode) a movie that has all ready been transcoded, quality will be reduced i suspect.
 
Idgit

Idgit

macrumors 6502a
Mar 14, 2004
551
158
It's already a high bitrate file, so I wouldn't worry about quality loss. Set Handbrake to RF18 and the difference will be negligible.

Or, given that your file is a Scene torrent, download a proper h.264/x264 BluRay rip.

JMEANS said:
but crap : ( really didnt want to handbreak (transcode) a movie that has all ready been transcoded, quality will be reduced i suspect.
Click to expand...
 
D

dynaflash

macrumors 68020
Mar 27, 2003
2,119
8
JMEANS said:
thanks everyone

but crap : ( really didnt want to handbreak (transcode) a movie that has all ready been transcoded, quality will be reduced i suspect.
Click to expand...
Yes, it will. but depending on what settings you use ... it is possible to reduce quality but have it all but visually undetectable depending on your source and settings. While I don't want to get into the semantics of what you can or cannot see ... it is possible *usually* (there again depending on source) to get a decent transcode to where you basically can not tell the difference with the naked eye.

However it looks like you have an xvid (divx) video track ... that does not bode well as they kind of suck to begin with ... pardon the expression.

While its outside the scope of this post ... video transcoding is a bit of a shell game when it comes to quality loss ... you can lose quality in places where the human eye has a hard time detecting it. If done properly ... you will never notice .. and frankly who cares about quality loss that you can't detect ? I know I don't. It may show up in some ssim or psnr number from the encoder but frankly typically that does not please the human eye.
 
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J

JMEANS

macrumors regular
Original poster
Jun 9, 2012
172
5
thanks guys, very familiar with HB and the ins and outs, i usually rip my own collection of blu's etc but i am finding HD versions of films like GHOSTBUSTERS 2 and JAWS 2 etc that have not yet been released on Blu, so i go looking on PB for HDTV captures such as this file to get an HD copy.

I will try HB and see if i notice a significant change and honestly I usually dont, my concern mainly was not wanting to reduce the file size any.

thanks again
 
M

mic j

macrumors 68030
Mar 15, 2012
2,663
156
dynaflash said:
.. and frankly who cares about quality loss that you can't detect ? I know I don't. It may show up in some ssim or psnr number from the encoder but frankly typically that does not please the human eye.
Click to expand...

I think you may have opened a can of worms with that statement, Dynaflash! :eek:

But I totally agree and wish we would get past this "anything that is not a bit-for-bit copy is unacceptable to watch". That approach causes a lot of people to spend a lot more time and money getting their movies on their media players than is necessary.
 
D

dynaflash

macrumors 68020
Mar 27, 2003
2,119
8
mic j said:
I think you may have opened a can of worms with that statement, Dynaflash! :eek:

But I totally agree and wish we would get past this "anything that is not a bit-for-bit copy is unacceptable to watch". That approach causes a lot of people to spend a lot more time and money getting their movies on their media players than is necessary.
Click to expand...

I thought the same thing right after I posted it. oh well in this case with an xvid video track there isn't much choice as remuxing is not an option if I understand the situation correctly.
 
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