Lossless audio or not?

Everything related to MakeMKV
Post Reply
ArieS
Posts: 24
Joined: Fri Sep 23, 2011 6:36 am

Lossless audio or not?

Post by ArieS »

Hello,
I'm kinda new to MakeMKV and I think I ran into a problem. I'm trying to rip my BD of Resident Evil: Afterlife.
I'm trying to get the lossless track for when XBMC supports it with Eden.
Anyway, it seems like a small file size for a lossless track. So I decided to rip the BD twice, the 1st time selecting the DTS-HD track and the 2nd time just the lossy DTS track.
A few observations: it seems the size of the audio tracks are pretty much the same, shouldn't the DTS HD one be much bigger??
Also here is what it says for the HD track: Bit rate: 1 561 Kbps / 1 510 Kbps, shouldn't the bitrate be much higher for a lossless track?

Here are the MediaInfo infos for both:

DTS HD:

General
Unique ID : 159766649045419464229807352741064866407 (0x7831EFF63DD6AAAA5AD7FDBE250FFA67)
Complete name : K:\#Movies 4\Resident Evil 4.Bluray.mkv
Format : Matroska
File size : 17.8 GiB
Duration : 1h 36mn
Overall bit rate : 26.4 Mbps
Encoded date : UTC 2011-09-23 05:23:01
Writing application : MakeMKV v1.6.15 win(x64-release)
Writing library : libmakemkv v1.6.15 (1.2.0/1.1.0) win(x64-release)

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 2 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 1h 36mn
Bit rate mode : Variable
Bit rate : 24.3 Mbps
Width : 1 920 pixels
Height : 1 080 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) : 0.488
Stream size : 16.4 GiB (92%)
Language : English

Audio
ID : 2
Format : DTS
Format/Info : Digital Theater Systems
Format profile : MA / Core
Codec ID : A_DTS
Duration : 1h 36mn
Bit rate mode : Variable
Bit rate : 1 561 Kbps / 1 510 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossless / Lossy
Title : Lossless
Language : English


DTS Lossy:

General
Unique ID : 228818392282118084920847759294041770763 (0xAC24D1C111F96AE75ABC0AAA7A454B0B)
Complete name : K:\Video\Resident_Evil_Afterlife lossy\title01.mkv
Format : Matroska
File size : 17.2 GiB
Duration : 1h 36mn
Overall bit rate : 25.5 Mbps
Encoded date : UTC 2011-09-23 05:50:27
Writing application : MakeMKV v1.6.15 win(x64-release)
Writing library : libmakemkv v1.6.15 (1.2.0/1.1.0) win(x64-release)

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 2 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 1h 36mn
Bit rate mode : Variable
Bit rate : 23.4 Mbps
Width : 1 920 pixels
Height : 1 080 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) : 0.471
Stream size : 15.9 GiB (92%)
Language : English

Audio
ID : 2
Format : DTS
Format/Info : Digital Theater Systems
Codec ID : A_DTS
Duration : 1h 36mn
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 : 16 bits
Compression mode : Lossy
Stream size : 1.02 GiB (6%)
Title : 3/2+1
Language : English


Hope my post is not too long.
Romansh
Posts: 873
Joined: Sat Jan 22, 2011 7:09 pm

Re: Lossless audio or not?

Post by Romansh »

ArieS wrote:Also here is what it says for the HD track: Bit rate: 1 561 Kbps / 1 510 Kbps, shouldn't the bitrate be much higher for a lossless track?
1561 + 1510 -> 3071 Kbps, which is perfectly reasonable given how this track is only 16-bit.
The uncompressed track would be 4608 Kbps.
ArieS
Posts: 24
Joined: Fri Sep 23, 2011 6:36 am

Re: Lossless audio or not?

Post by ArieS »

Romansh wrote:
ArieS wrote:Also here is what it says for the HD track: Bit rate: 1 561 Kbps / 1 510 Kbps, shouldn't the bitrate be much higher for a lossless track?
1561 + 1510 -> 3071 Kbps, which is perfectly reasonable given how this track is only 16-bit.
So I'm supposed to add these numbers?
The uncompressed track would be 4608 Kbps.
This was supposed to be the uncompressed track... :?

Also, here's Return of the Jedi:

Audio
ID : 2
Format : DTS
Format/Info : Digital Theater Systems
Format profile : MA / Core
Codec ID : A_DTS
Duration : 2h 14mn
Bit rate mode : Variable
Bit rate : 1 510 Kbps
Channel(s) : 7 channels / 6 channels
Channel positions : Front: L C R, Side: L R, Back: C, LFE / Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 24 bits
Compression mode : Lossless / Lossy
Stream size : 1.42 GiB (4%)
Title : Lossless
Language : English

Why is it only 1510 Kbps? And the stream size is only 1.42 GB while the total MKV is 33 GB

Can someone post what they get in MediaInfo for this movie? Doesn't seem I have the DTS-HD track...
SamuriHL
Posts: 2259
Joined: Mon Jun 14, 2010 5:32 pm

Re: Lossless audio or not?

Post by SamuriHL »

ArieS wrote: Also, here's Return of the Jedi:

Audio
ID : 2
Format : DTS
Format/Info : Digital Theater Systems
Format profile : MA / Core
Codec ID : A_DTS
Duration : 2h 14mn
Bit rate mode : Variable
Bit rate : 1 510 Kbps
Channel(s) : 7 channels / 6 channels
Channel positions : Front: L C R, Side: L R, Back: C, LFE / Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 24 bits
Compression mode : Lossless / Lossy
Stream size : 1.42 GiB (4%)
Title : Lossless
Language : English
Why is it only 1510 Kbps? And the stream size is only 1.42 GB while the total MKV is 33 GB

Can someone post what they get in MediaInfo for this movie? Doesn't seem I have the DTS-HD track...
See what I bolded? Now, when you look at the rest of the information, the left side of the / is for the MA part and the right side of the / is for the core. So, see Lossless / Lossy. DTS-HD MA is an EXTENSION of the core. The bitrate being reported is for the core. There is *NO WAY* a core only track is taking 1.42 gigs! :)
ArieS
Posts: 24
Joined: Fri Sep 23, 2011 6:36 am

Re: Lossless audio or not?

Post by ArieS »

SamuriHL,
Thanks, I see now the 2 columns...
And so, 1.42 GB for the lossless track sounds about right to you?
Oh and I still don't get why the Bit rate is only 1 510 Kbps...
SamuriHL
Posts: 2259
Joined: Mon Jun 14, 2010 5:32 pm

Re: Lossless audio or not?

Post by SamuriHL »

Yea, 1.42 gigs for a lossless compressed DTS-HD MA track definitely sounds right. As for the bitrate report, that's all they can show. DTS-HD MA extensions aren't publicly exposed as to how to decode so there's no easy way to show that bitrate in an open source tool. It's nothing to be concerned about at all. Trust me, you have a DTS-HD MA track. If you bitstream it, you will get the HD audio you want.
ArieS
Posts: 24
Joined: Fri Sep 23, 2011 6:36 am

Re: Lossless audio or not?

Post by ArieS »

Thanks a lot SamuriHL !
Romansh
Posts: 873
Joined: Sat Jan 22, 2011 7:09 pm

Re: Lossless audio or not?

Post by Romansh »

ArieS wrote:This was supposed to be the uncompressed track... :?
No. DTS-HD MA and TrueHD are lossless, but compressed; otherwise they wouldn't be DTS-HD MA or TrueHD, they'd be LPCM.
SamuriHL wrote:There is *NO WAY* a core only track is taking 1.42 gigs! :)
SamuriHL wrote:Yea, 1.42 gigs for a lossless compressed DTS-HD MA track definitely sounds right.
Please check your math ;-)

2 h. 14 m. -> 134 m. -> 8040 s.

1.42 GiB -> 1454 MiB -> 1488978 KiB -> 1524713390 bytes -> 12197707121 bits

12197707121 / 8040 = 1517128 bps -> 1517 Kbps

As for why MediaInfo reports the track as only 1.42 GB, my guess is that it computes the stream size from the misdetected bitrate.
SamuriHL
Posts: 2259
Joined: Mon Jun 14, 2010 5:32 pm

Re: Lossless audio or not?

Post by SamuriHL »

Romansh wrote: Please check your math ;-)

2 h. 14 m. -> 134 m. -> 8040 s.

1.42 GiB -> 1454 MiB -> 1488978 KiB -> 1524713390 bytes -> 12197707121 bits

12197707121 / 8040 = 1517128 bps -> 1517 Kbps

As for why MediaInfo reports the track as only 1.42 GB, my guess is that it computes the stream size from the misdetected bitrate.
:oops: You are correct, of course. I'm not used to dealing with separated streams in terms of raw size. 1.42 gigs seems big for a core track, but, your math does look correct, so, point taken. I do agree that MediaInfo does not have the code needed to properly parse the MA extensions to the core track so bitrate and, as you point out, size are coming from the core track. My bad.
ArieS
Posts: 24
Joined: Fri Sep 23, 2011 6:36 am

Re: Lossless audio or not?

Post by ArieS »

Thanks Romansh for the additional infos.
Post Reply