View Full Version : Getting the Correct Audio/Video Bitrate on PCs and Macs

2005-08-24, 02:04 PM
I've seeded a couple of DVDs that I did not author. When I went to seed them, I opened the VOB in MPegInfo (Mac) and got the Audio and Video Bitrate. However, I soon realized that every VOB I opened with MPegInfo would give me different information on the Audio Bitrate (but the same for the Video Bitrate). So, I downloaded and installed GSpot on my PC and opened those same VOBs with GSpot and finally got the correct Audio Bitrate for the DVD. But, now I'm hearing that both of those applications are giving the Maximum Video Bitrate, not the Average. I've been told that PowerDVD will give the average, but I just looked into that and it isn't free (although I can get a free 30 trial). I have a friend who can't install GSpot (he runs Win 98 and it won't install for him) and he has PowerDVD, so he can get the Average Video Bitrate for any DVD he seeds, however he says that it won't give him the Audio Bitrate!

So, I'm just wondering....

first off, is there another (freeware) program to use on the Mac that will give acurate Audio Bitrate and Codec information? And, how about giving the Average Video Bitrate?

and then, for the PC, is there a freeware program that will give both the Audio Bitrate as well as the Average Video Bitrate?

2005-08-24, 02:18 PM

i haven't done much "in depth" testing of these programs, but they're the three i found when researching...don't have the links right now, sorry Lynne

2005-08-24, 02:25 PM
For t'Mac I'd recommend MPEG Streamclip (http://www.alfanet.it/squared5/mpegstreamclip.html). Open up a VOB and hit cmd-i.

2005-08-24, 02:41 PM
OK, I downloaded MPEGStreamclip and I get this for the U2 DVD I recently seeded:

Duration: 2:03:00
Data Size: 3.90 GB
Bit Rate: 4.54 Mbps

Video Tracks:
224 MPEG-2, 720 480, 4:3, 29.97 fps, 9.30 Mbps, lower field first

Audio Tracks:
128 AC3 2/0, 48 kHz, 192 kbps

Stream Files:
VTS_02_1.VOB (1000.00 MB)
VTS_02_2.VOB (1000.00 MB)
VTS_02_3.VOB (1000.00 MB)
VTS_02_4.VOB (993.45 MB)

So, it appears that it is at least agreeing with GSpot regarding the Audio codec and bitrate (AC3 and 192 kbps). But, it also says the Video bitrate is 9.30 Mbps. Is that the max bitrate and then 4.54 Mbps is the average?

2005-08-24, 02:49 PM
I'm not sure what that first number is for, but I don't think it's average bit rate. Here's what I get for gd1980-10-31d1:
Stream: VTS_01_1.VOB
Type: VOB program stream

Duration: 0:49:57
Data Size: 3.75 GB
Bit Rate: 10.76Mbps

Video Tracks:
224 MPEG-2, 704 480, 4:3, 29.97 fps, 9.80 Mbps , upper field first

Audio Tracks:
160 PCM stereo, 48 kHz, 1.54 Mbps

Stream Files:
VTS_01_1.VOB (1000.00 MB)
VTS_01_2.VOB (1000.00 MB)
VTS_01_3.VOB (1000.00 MB)
VTS_01_4.VOB (845.08 MB)

Here's Mattman's info:
Video Source: Low generation closed circuit pro-shot broadcast
(704 x 480 29.97fps NTSC VBR, average=8528 Kbps , peak=9831 Kbps )

Audio Source Set 1: PreFM>MSR>R>C>DAT>WAV>SHN
Audio Source Sets 2 and 3: MSR>R>C>DAT>WAV>SHN
(LPCM 1536 Kbps Stereo 48Khz)

It gets the audio info correct but only gives the max bitrate. I'm not sure what that other # is because it's not the avg for this disc...

2005-08-24, 02:53 PM
Hmmm, I'll have to take a look at the other applications that Aaron listed. At least, though, I can get accurate Audio info using MPEGStreamclip.

2005-08-24, 03:08 PM
ffmpeg wasn't any help (at least that I could see), and I don't know about the third program. It looks like there may not be a program on Mac to get avg bitrate.

2005-08-24, 03:31 PM
I just tried MacDVDBitrateParanoia ( and it seemed to work just fine at getting the Average Video Bitrate for another DVD I have on my drive, it didn't do well for the U2 one I list above at all. It would only look at 42 seconds of it and give me the average for that.

So, as you said gsmyth, I'm back to square one for the average video bitrate on a Mac.

(And no one has chipped in about a freeware program to get that on the PC.)

2005-08-24, 09:50 PM
Here are a couple of programs you can use to determine the average bitrate for a VOB/m2v file.

Bitrate Viewer v1.5


Although DVD-Lab is an authoring package, it includes a built in bitrate viewer. Just import the VOB/m2v file into the assets bin and then drag it onto the main screen. In the menu there is an option to run the bitrate viewer.

Regarding PowerDVD - this will give you the actual bitrate in real time for any point in the video. Just right click on the video while it's playing and select "Show Information". The audio bitrate and codec (ie. AC3/PCM/etc.) will also be displayed on the screen.

None of these programs are freeware, but they do have 30 day trials.

FYI, if you have a regular single layered DVDR (4.7 GB) you can fit approximately 60 minutes of video footage at the maximum DVD bitrate (9800kbit/sec). Therefore if you completely fill the disc with 2 hours of footage the average bitrate will effectively be halved.
Note: this is a simplistic way of looking at it. There are many factors that may affect the average bitrate (such as the audio bitrate (PCM vs AC3), the size of the menus (motion menus can be huge!), multiple audio streams)

Some people have reported incorrect results from Bitrate Viewer v1.5, so it would be best to try your DVD in a number of programs. Only the original encoder will have the correct information as they are the ones entering the min/averag/max figures in their encoder (assuming they're doing VBR encoding). If they're using a standalone encoder then this information won't be as readily available, but people shouldn't be using standalone recorders to encode footage anyway...

I hope this helps.