Is there a way to see how big the audio part is in a mkv?

[AndyD]

I used the xstream option in Ripbot on a movie which is a bit big than my usual rips. I thought it was because of the lower CRF but it didn't make a difference when I increased it. Anyway, just curious what the difference is in size when I use xstream vs the other options

[guns1inger]

MediaInfo or mxvextract

[AndyD]

Where in mediainfo would I see that info? I tried that first before posting but I don't see file size info

[edDV]

Where in mediainfo would I see that info? I tried that first before posting but I don't see file size info

Post the text view of your file info.

[AndyD]

General
Complete name : E:\road.mkv
Format : Matroska
File size : 20.6 GiB
Duration : 1h 57mn
Overall bit rate : 25.1 Mbps
Movie name : road
Encoded date : UTC 2010-11-16 22:41:35
Writing application : mkvmerge v4.1.1 ('Bouncin' Back') built on Jul 3 2010 22:54:08
Writing library : libebml v1.0.0 + libmatroska v1.0.0

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.0
Format settings, CABAC : Yes
Format settings, ReFrames : 3 frames
Format settings, GOP : M=4, N=48
Muxing mode : Container profile=Unknown@4.0
Codec ID : V_MPEG4/ISO/AVC
Duration : 1h 57mn
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
Writing library : x264 core 104 r1683 62997d6
Encoding settings : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=6 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / constrained_intra=0 / bframes=3 / b_pyramid=0 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=240 / keyint_min=24 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=14.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / vbv_maxrate=25000 / vbv_bufsize=25000 / crf_max=0.0 / ip_ratio=1.40 / aq=1:1.00 / nal_hrd=vbr

Audio
ID : 2
Format : FLAC
Format/Info : Free Lossless Audio Codec
Codec ID : A_FLAC
Duration : 1h 57mn
Bit rate mode : Variable
Channel(s) : 6 channels
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Writing library : libFLAC 1.2.1 (UTC 2007-09-17)

Menu
00:00:00.000 : en:00:00:00.000
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00:55:58.105 : en:00:55:58.105
00:58:57.909 : en:00:58:57.909
01:03:32.017 : en:01:03:32.017
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01:35:55.959 : en:01:35:55.959
01:41:33.879 : en:01:41:33.879
01:43:32.081 : en:01:43:32.081
01:50:37.089 : en:01:50:37.089

[guns1inger]

Apologies. I was on the wrong machine when I responded earlier, and couldn't confirm the output. Looks like I was wrong about mediainfo showing this.

[edDV]

Hmm, not clear from that info

"Overall bit rate : 25.1 Mbps"

FLAC audio "losslessly" compresses 50-60%. 6x 16 bit, 48 KHz channels uncompressed would be ~4.6 Mbps so FLAC should take that down ~ 50% to ~2.3 Mbps.

[AlanHK]

MKVExtractGUI -- doesn't tell you how big it is, but you can just extract the audio as a separate file easily and check it out.

[intracube]

Apologies. I was on the wrong machine when I responded earlier, and couldn't confirm the output. Looks like I was wrong about mediainfo showing this.

The command line version of mediainfo (for Linux) does:

Audio
ID                               : 4352 (0x1100)
Menu ID                          : 1 (0x1)
Format                           : AC-3
Format/Info                      : Audio Coding 3
Mode extension                   : CM (complete main)
Duration                         : 24s 928ms
Bit rate mode                    : Constant
Bit rate                         : 256 Kbps
Channel(s)                       : 2 channels
Channel positions                : Front: L R
Sampling rate                    : 48.0 KHz
Bit depth                        : 16 bits
Video delay                      : -80ms
Stream size                      : 779 KiB (2%)

MediaInfo Command line,
MediaInfoLib - v0.7.34

EDIT: Mediainfo 0.7.36 for Windows also shows the audio stream size. AndyD, what version have you got?

[AndyD]

Thanks guys. I ended up extracting the video file using mkvextract since I couldn't extract the FLAC audio (not supported it seems). I found this to be really strange...

The video file is 19gb while the audio was a little over 1gb - does that make sense? For FLAC? I guess I was expecting a larger file.

[AndyD]

EDIT: Mediainfo 0.7.36 for Windows also shows the audio stream size. AndyD, what version have you got?

I have 0.7.34 installed

[intracube]

I have 0.7.34 installed

I've created several .mkv files with different audio codecs (FLAC,MP2,MP3,AC3,PCM). The versions of mediainfo that I've tried (including 0.7.34) don't show the audio stream size for FLAC or PCM audio. Not sure why, though.

[AndyD]

Ok thanks. I'll check out a later version. Now just wondering about the results from extracting.

Is 1gb for audio expected for FLAC?

[AlanHK]

Ok thanks. I'll check out a later version. Now just wondering about the results from extracting.

Is 1gb for audio expected for FLAC?

Not for 3 minutes. Maybe for an hour or two.
Also depends on how many channels.


Any valid FLAC files from a particular audio will be close to the same size, regardless of settings.
Generally, about 30-50% less than the equivalent WAVE file.
FLAC is lossless, and the difference between the highest and lowest compression settings is a few percent, at the cost of longer analysing time to create it.

The FLAC frontend (GUI) includes a "test" function.

See http://flac.sourceforge.net/faq.html

[AndyD]

It's a 2 hour video - 1gb FLAC is ok then? I don't know...I guess I was expecting something larger than that

[AndyD]

Anyone? I'm holding off on backing up any more of my blurays till I know this. Will use FLAC if there really isn't going to be any real difference in size. I would have expected the audio to be around 4-5gb

[intracube]

FLAC audio "losslessly" compresses 50-60%. 6x 16 bit, 48 KHz channels uncompressed would be ~4.6 Mbps so FLAC should take that down ~ 50% to ~2.3 Mbps.

Only 5 channels are sampled at 48kHz, the '.1' LFE would have a negligible effect on bit-rate. So that would make it ~1.9Mbps.

It's a 2 hour video - 1gb FLAC is ok then?

I would guess around 1.7GB for 2 hours.

I would have expected the audio to be around 4-5gb

'gb' isn't a valid unit of file-size. GB = gigabyte, Gb = gigabit. 1GB is the same as 8Gb.
Both GB and Gb are used regularly, although Gb/Mb/kb is often used for streaming data and GB/MB/kB for static files.

[AlanHK]

Anyone? I'm holding off on backing up any more of my blurays till I know this. Will use FLAC if there really isn't going to be any real difference in size. I would have expected the audio to be around 4-5gb

I don't know what you're worried about.

If the the FLAC audio has all the channels, at the full length, then it should be perfect.