Register FAQ / Rules Forum Spy Search Today's Posts Mark Forums Read
Go Back   MacRumors Forums > Apple Hardware > Apple TV and Home Theater

Reply
 
Thread Tools Search this Thread Display Modes
Old Aug 15, 2012, 07:18 PM   #1
hankkosovo
macrumors member
 
Join Date: Jul 2009
Converted MKV to M4V and went from 9.39GB to 3.21GB is this normal?

I used the ATV3 settings in hand brake and I'm just puzzled how the file size has been reduced so much when the quality seems the same, can anyone shed some light on this?
hankkosovo is offline   0 Reply With Quote
Old Aug 15, 2012, 07:19 PM   #2
simsaladimbamba
Guest
 
Join Date: Nov 2010
Location: located
In order to find out, what is the cause of the file size reduction (it is a lowered bitrate), you can use the following three applications to analyse the source .mkv and resulting .mp4.
When done, you can use the "Report" (VideoSpec) and "Export" (Media Inspector) button to export a report,
attachable to your next post via the button.
In MediaInfo you have to go to the Menu Bar, select View > Text and copy the text via CMD+A > CMD+C and paste it via CMD+V into your next post.
simsaladimbamba is offline   0 Reply With Quote
Old Aug 15, 2012, 08:26 PM   #3
mic j
macrumors 68000
 
Join Date: Mar 2012
Quote:
Originally Posted by hankkosovo View Post
I used the ATV3 settings in hand brake and I'm just puzzled how the file size has been reduced so much when the quality seems the same, can anyone shed some light on this?
I think that is reasonable. A lot of my dvd are 1GB from 5-6GB. It really varies because of the source, but if I got that I would not even question it.
__________________
17" MBP '09, 2.66 GHz, 8GB RAM; 13" MBP (Retina) '12, 2.5GHz, 8GB RAM; iPad 2, 32GB; AE; TV 3; AEBS w 1TB Seagate HDD; 65" Mits DLP, Sony STR-DB1070 AVR
mic j is offline   0 Reply With Quote
Old Aug 15, 2012, 08:33 PM   #4
simsaladimbamba
Guest
 
Join Date: Nov 2010
Location: located
Quote:
Originally Posted by mic j View Post
I think that is reasonable. A lot of my dvd are 1GB from 5-6GB. It really varies because of the source, but if I got that I would not even question it.
Video DVDs use the MPEG-2 codec (old), which is not that space efficient and are from 4 to 8 GB in size, .mp4 files use the H.264 codec (newer MPEG-4 codec), which is quite space efficient, thus the smaller file size. .mkv files typically use H.264 or x264 (also an MPEG-4 codec), thus a file size reduction might also come with a reduction in visible image quality or even resolution reduction.
simsaladimbamba is offline   0 Reply With Quote
Old Aug 15, 2012, 09:55 PM   #5
mic j
macrumors 68000
 
Join Date: Mar 2012
Quote:
Originally Posted by simsaladimbamba View Post
Video DVDs use the MPEG-2 codec (old), which is not that space efficient and are from 4 to 8 GB in size, .mp4 files use the H.264 codec (newer MPEG-4 codec), which is quite space efficient, thus the smaller file size. .mkv files typically use H.264 or x264 (also an MPEG-4 codec), thus a file size reduction might also come with a reduction in visible image quality or even resolution reduction.
MPEG2 is not old, it's currently in use on every standard dvd. h.264 is used on BR's as they are compressed from original material. Only torrented mkv's are h.264 which means they have been compressed from a mpeg2 or BR. What's your point?
__________________
17" MBP '09, 2.66 GHz, 8GB RAM; 13" MBP (Retina) '12, 2.5GHz, 8GB RAM; iPad 2, 32GB; AE; TV 3; AEBS w 1TB Seagate HDD; 65" Mits DLP, Sony STR-DB1070 AVR
mic j is offline   0 Reply With Quote
Old Aug 15, 2012, 10:02 PM   #6
simsaladimbamba
Guest
 
Join Date: Nov 2010
Location: located
Quote:
Originally Posted by mic j View Post
MPEG2 is not old, it's currently in use on every standard dvd. h.264 is used on BR's as they are compressed from original material. Only torrented mkv's are h.264 which means they have been compressed from a mpeg2 or BR. What's your point?
MPEG-2 is old compared to MPEG-4, for me it is old, since it is a storage space inefficient codec.
As for what my point is, the size reduction is dependent on what resolution, codec and bit-rate the source had and what resolution, codec and bit-rate the target file has.
Another part of my point is, that transcoding MPEG-2 to MPEG-4 almost always results in smaller sizes, as video DVDs use a bit-rate of 5 to 8 Mb/s, while H.264 encoded videos use 1 to 2 Mb/s, often even less. MPEG-4 is more space efficient.

I know .mkv is a container for many codecs, MPEG-4 is the one use most often though, and 9 GB sounds like an HD rip of a Blu-Ray using some MPEG-4 variant as codec.
simsaladimbamba is offline   0 Reply With Quote
Old Aug 16, 2012, 12:07 AM   #7
MacinJosh
macrumors 6502a
 
Join Date: Jan 2006
Location: Finland
Don't forget that there are several profiles within the H.264 spec of varying quality. A High Profile level 4.1 can go down in file size significantly while retaining quality, something Low or Main Profile can't come near to.

And yes, MPEG2 *is* old. Almost 20-years.
__________________
Mac Pro 5,1 Quad 2.8Ghz - 5770 - 12GB - 120GB SSD - 6TB
MBA 2013 - 11" - 8GB - 128GB
Apple TV3 / iPhone 4S - 16GB / iPhone 4 - 16GB
iPad Mini Retina - 32GB / iPad 3 - 16GB - Black

Last edited by MacinJosh; Aug 16, 2012 at 12:13 AM.
MacinJosh is offline   0 Reply With Quote
Old Aug 17, 2012, 07:54 AM   #8
hankkosovo
Thread Starter
macrumors member
 
Join Date: Jul 2009
Quote:
Originally Posted by simsaladimbamba View Post
In order to find out, what is the cause of the file size reduction (it is a lowered bitrate), you can use the following three applications to analyse the source .mkv and resulting .mp4.
When done, you can use the "Report" (VideoSpec) and "Export" (Media Inspector) button to export a report,
attachable to your next post via the Image button.
In MediaInfo you have to go to the Menu Bar, select View > Text and copy the text via CMD+A > CMD+C and paste it via CMD+V into your next post.
Thanks for the info! Here are the reports:

9.39GB:

Code:
***** Analyzed File Results *****

*** General Parameters ***
- Name:  fhd-antichrist.1080p.mkv 
- Container:  Matroska 
- Size:  9.395 GB 
- Duration:  1h 44mn 
- Bitrate:  12.0 Mbps 

*** Video Track Parameters ***
- Format:  H.264/MPEG-4 AVC 
- Bitrate:  Max.: Undefined / Average: 9 012 Kbps / Min.: Undefined 
- Frame rate (fps):  Max.: Undefined / Average: 25.000 / Min.: Undefined 
- Encoding profile:  High@L4.1 
- Image size:  1920*816 
- Pixel Aspect Ratio:  Undefined 
- Display Aspect Ratio:  2.35:1 
- Interlacing:  Progressive 

*** First Audio Track Parameters ***
- Format:  DTS Coherent Acoustics 
- Bitrate:  1 510 Kbps 
- Resolution:  16 bits 
- Rate:  48.0 KHz 
- Channel(s):  5:1 - 6 channels 
- Position:  Front: L C R, Side: L R, LFE 

*** Miscellaneous ***
- Subtitle(s): #1 : UTF-8 - French / #2 : UTF-8 - French / 
- Album: Undefined
- Performer: Undefined
- Genre: Undefined
- Encoded date: UTC 2009-11-04 23:04:58
- Album artist: Undefined
3.21GB

Code:
***** Analyzed File Results *****

*** General Parameters ***
- Name:  Antichrist 1080p.m4v 
- Container:  M4V - QuickTime 
- Size:  3.21 GB 
- Duration:  1h 44mn 
- Bitrate:  4 113 Kbps 

*** Video Track Parameters ***
- Format:  H.264/MPEG-4 AVC 
- Bitrate:  Max.: Undefined / Average: 3 308 Kbps / Min.: Undefined 
- Frame rate (fps):  Max.: --- / Average: 25.000 / Min.: --- 
- Encoding profile:  High@L4.0 
- Image size:  1920*816 
- Pixel Aspect Ratio:  Undefined 
- Display Aspect Ratio:  2.35:1 
- Interlacing:  Progressive 

*** First Audio Track Parameters ***
- Format:  AAC - MPEG-4 audio 
- Bitrate:  160 Kbps 
- Resolution:  Undefined 
- Rate:  48.0 KHz 
- Channel(s):  2 (stereo) 
- Position:  Front: L R 

*** Miscellaneous ***
- Subtitle(s): No Subtitle
- Album: Undefined
- Performer: Undefined
- Genre: Undefined
- Encoded date: UTC 2012-08-06 15:05:15
- Album artist: Undefined
It looks like the bit rate has been reduced, is there anyway to stop this in handbrake?
hankkosovo is offline   0 Reply With Quote
Old Aug 17, 2012, 08:13 AM   #9
J@ffa
macrumors 6502a
 
J@ffa's Avatar
 
Join Date: Jul 2002
Location: Behind you!
You don't need to convert that file — the Apple TV can play it natively. It's a common problem both here and elsewhere because this process is a bit confusing, but I'll try to explain it as simply as I can.

MKV files are containers, which can hold a variety of video and audio formats. In your case, the file you've… acquired (ahem ) has H.264 video in it and DTS audio. In terms of containers, the Apple TV only supports the .m4v and .mp4 containers. These are essentially identical, but the .m4v extension is better for either chapters or subtitles (can't remember which, but this is a minor detail). In theory, you can use a software tool to drop the H.264 video and DTS audio into an .m4v/.mp4 container, which would take you the time it takes to copy those files, plus a little extra time to do some special stuff that makes the file play nicely with the Apple TV. The bit where you move the files into a different container is called muxing (or, more accurately, 'remuxing').

However, the Apple TV doesn't support DTS audio. So what you need to do is use a tool that can convert that DTS 5.1 audio into Dolby 5.1, which the Apple TV does support — and, while you're there, add a 2.0 stereo downmix so the file you've got can be played via iTunes/QuickTime on your Mac and any iOS devices you may have. This bit is optional, but the better tools will do it by default, since audio encoding doesn't take particularly long and it doesn't hurt to futureproof your files.

There are dozens of ways to do what I've described, and I've tried most of them. The one I'd recommend most highly is iFlicks, which is a drag and drop affair. Drop the Antichrist MKV onto the window, select the 'iTunes compatible' preset, and wait (usually this process takes 10-20 minutes in all, depending). The resultant file will be the same size as the original, give or take a few hundred megabytes (which'll account for the extra audio track). You'll also have no video quality loss, since the H.264 video track will be exactly the same as it is in the .mkv.

Good luck!
J@ffa is offline   1 Reply With Quote

Reply
MacRumors Forums > Apple Hardware > Apple TV and Home Theater

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Similar Threads
thread Thread Starter Forum Replies Last Post
MKV to M4V Question WSFrazier Apple TV and Home Theater 13 Sep 14, 2013 04:55 PM
Cover art for DVDs converted to m4v mrmarts Apple TV and Home Theater 18 May 17, 2013 02:29 PM
MKV to M4V Container Change mic j Apple TV and Home Theater 32 Nov 28, 2012 05:53 AM
How do you remux M4V to MKV? Jim.R Apple TV and Home Theater 12 Oct 29, 2012 04:30 AM
Mkv to mp4/m4v lossless Spacecowboy1 Apple TV and Home Theater 66 Oct 7, 2012 04:55 PM

Forum Jump

All times are GMT -5. The time now is 01:30 PM.

Mac Rumors | Mac | iPhone | iPhone Game Reviews | iPhone Apps

Mobile Version | Fixed | Fluid | Fluid HD
Copyright 2002-2013, MacRumors.com, LLC