finding audio bitrate in video files

[AlanHK]

When assessing and comparing video files one important consideration is the bitrate.

Tools like Mediainfo show the video and audio bitrates for some kinds of files, but not for all, specifically AVC/AAC in MKV often do not have bitrates.

I found "Bitrate Viewer" which does quickly show the video bitrate for every kind of video I've tried, but for audio nothing seems to work.
Some players will show you the instantaneous bitrate, which is interesting, but for VBR I want the average over the entire file.

Is there a tool that saves me the hassle of demuxing the audio, reading off the filesize and duration and calculating by hand?

[Cornucopia]

You already know this, but: "Filesize = Bitrate * Running Time". So you could use "your brain" as a tool to figure out what the bitrate is. Even if MediaInfo cannot parse & present all the headers necessary, I bet it can tell you the filesize (both in total and individually/in proportion), so since you know the running time, you can use the above formula to get the rest.

But, I use MI as much as the next guy and love to see it getting even more thorough. I wouldn't be surprised if those few files that don't currently have their bitrate details explained will probably be able to in future builds.

Scott

[AlanHK]

You already know this, but: "Filesize = Bitrate * Running Time". So you could use "your brain" as a tool to figure out what the bitrate is.

Why the compulsion to tell me things I already know?

Even if MediaInfo cannot parse & present all the headers necessary, I bet it can tell you the filesize (both in total and individually/in proportion), so since you know the running time, you can use the above formula to get the rest.

You lose your bet.
See the below complete report on an MKV.
No bitrate and no stream filesize.


Video bitrate I can get from "Bitrate Viewer".
It gives me average = 1463 kbps

If the file was just one video and one audio stream I could estimate it by subtracting the video from the overall bitrate.
1636-1463 = 173 kbps

But this has subtitles, so audio will be a bit less. If there were more audio streams, it would be impossible to work out this way.

I can only reliably work out audio bitrate by actually demuxing the file.
That gave me an AAC file, 53 MB, and "my brain" gives me 158 kbps
Or opening the AAC with an audio app, it says 161 kbps CBR.
Close enough.


So I can get the answer in the end, but demuxing creates a bunch of potentially large files and takes time.

That's why I was enquiring if there was an easier method. Not because I need to be lectured on primary school arithmetic.

General
Unique ID                                : 125188158741917638921711956426614289813 (0x5E2E5CC3A64D1955EC4F5C47D66AB595)
Complete name                            : Ep1.mkv
Format                                   : Matroska
Format version                           : Version 2
File size                                : 529 MiB
Duration                                 : 45mn 10s
Overall bit rate                         : 1 636 Kbps
Writing application                      : HandBrake 0.9.5
Writing library                          : libmkv 0.6.4.1

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L3.0
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 4 frames
Codec ID                                 : V_MPEG4/ISO/AVC
Duration                                 : 45mn 10s
Width                                    : 720 pixels
Height                                   : 576 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 25.000 fps
Standard                                 : PAL
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Writing library                          : x264 core 112
Encoding settings                        : cabac=1 / ref=2 / deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=6 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=0 / 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=2 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=0 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=20.0 / qcomp=0.60 / qpmin=3 / qpmax=51 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Language                                 : English
Default                                  : Yes
Forced                                   : No
Color primaries                          : BT.601 NTSC
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.601

Audio
ID                                       : 2
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : A_AAC
Duration                                 : 45mn 10s
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 KHz
Compression mode                         : Lossy
Language                                 : English
Default                                  : Yes
Forced                                   : No

Text
ID                                       : 3
Format                                   : VobSub
Codec ID                                 : S_VOBSUB
Codec ID/Info                            : The same subtitle format used on DVDs
Language                                 : English
Default                                  : No
Forced                                   : No

Menu
00:00:00.000                             : Chapter 1
00:08:08.800                             : Chapter 2
00:16:42.560                             : Chapter 3
00:24:11.840                             : Chapter 4
00:32:24.280                             : Chapter 5
00:40:22.160                             : Chapter 6

[poisondeathray]

avinaptic can for some types of containers like mkv, mp4, avi - but you have to do the full analysis (misc=>full analysis) and it might take a minute depending on how big the file is because it scans it like bitrate viewer or gspot.

[Cornucopia]

You already know this, but I was "compelled" to.

Yes, the addition of other streams would complicated things. But text? chapters? subs? At best, they would add ~1kbps to the whole equation, so can be ignored.
Now, if you had multiple audio or video streams, that would be another matter.

How hard is it to demux audio, though?

Here's a suggestion you might like: Get the optional, modded ffmpeg library as a plugin for Audacity. Then, you can open up the audio directly in Audacity without demuxing. However, it still won't get you bitrate listing.

Another suggestion: use "Advanced Mode" in MediaInfo. It might reveal some bits about bitrate that are hidden in the default mode.

But why are you compelled to get so irate about a lighthearted suggestion?

Scott

<edit>pdr's avinaptic suggestion is better</edit>

[DarrellS]

Install Matroskaprop and configure and when you hover over a Matroska file, it will show the properties including audio and video bitrate.


http://www.softpedia.com/get/System/OS-Enhancements/MatroskaProp.shtml

[Cornucopia]

If that app can do it, surely MediaInfo ought to be able to as well...

[AlanHK]

avinaptic can for some types of containers like mkv, mp4, avi - but you have to do the full analysis (misc=>full analysis) and it might take a minute depending on how big the file is because it scans it like bitrate viewer or gspot.

Yes! It works. Bitrates and stream sizes both.
Thanks.

Video track

Codec ID                    V_MPEG4/ISO/AVC
Resolution                  720 x 576
Display resolution          1024 x 576 (pixels)
Frame aspect ratio          5:4 = 1.25
Pixel aspect ratio          64:45 = 1.422222
Display aspect ratio        16:9 = 1.777778
Framerate                   25 fps
Stream size                 495,881,145 bytes (472.909112 MiB)
Duration (bs)               00:45:11 (2710.72 s)
Bitrate (bs)                1463.466961 kbps
Qf                          0.141152

Audio track

Codec ID                    A_AAC
Sampling frequency          48000 Hz
Channels                    2
Stream size                 54,174,407 bytes (51.664741 MiB)
Bitstream type (bs)         AAC LC (Low Complexity)
Frames (bs)                 127,007
Duration (bs)               00:45:09 (2709.482667 s)
Chunk-aligned (bs)          Yes
Bitrate (bs)                159.954984 kbps VBR
Sampling frequency (bs)     48000 Hz
Mode (bs)                   2: front-left, front-right

[AlanHK]

Install Matroskaprop and configure and when you hover over a Matroska file, it will show the properties including audio and video bitrate.


http://www.softpedia.com/get/System/OS-Enhancements/MatroskaProp.shtml

Doesn't show bitrates for me.
Didn't really expect it to, I already tried MKVinfo, and neither did that.

Yes, the addition of other streams would complicated things. But text? chapters? subs? At best, they would add ~1kbps to the whole equation, so can be ignored.
Now, if you had multiple audio or video streams, that would be another matter.

Why do you keep repeating things that I already said?

How hard is it to demux audio, though?

Not at all. Just tedious. AS I SAID.

Here's a suggestion you might like: Get the optional, modded ffmpeg library as a plugin for Audacity. Then, you can open up the audio directly in Audacity without demuxing. However, it still won't get you bitrate listing.

On opening a media file Audacity expands the audio to an uncompressed format, creating gigabytes of temporary files and takes several minutes for a long video file.
And at the end, you have no information at all about the original audio stream compression.

This is absolutely the most inane suggestion so far.

Another suggestion: use "Advanced Mode" in MediaInfo. It might reveal some bits about bitrate that are hidden in the default mode.

It doesn't.

But why are you compelled to get so irate about a lighthearted suggestion?

Why are you so compelled to waste my time with irrelevant and patronising suggestions?

Anyway, Avinaptic gives the info I want, so we can consider the topic closed

[DarrellS]

That's weird cause last night it used MatroskaProp to show bitrate in MKVs but today it's using Mediainfo.

[poisondeathray]

@DarrellS - does it show it for AAC audio as well? or just AC3 ?

Could it have to do with the splitter used (e.g. haali vs. lav ) ? or do you need a specific config for it to work ?

[DarrellS]

Took a while to find MKV with AAC. Most of my MKV have AC3. No, AAC does not show bit rate in MKV and even worse, in MP4, it shows nothing for video or audio.

I also have dBpoweramp and when I hover over an MPEG file, it shows all the audio info.