gspot question/problem

[datdork]

the program not the.....well you know

been using v2.52 for a while now. a while back I downloaded 2.6 but never installed it. grabbed 2.7 today.

anyway not sure what is going on. with 2.52 when you drag a VOB file into it it instantly shows the bit rate etc. with the newer versions it goes through a whole process (bit rate numbers change a bunch) and then shows the bit rate etc.

thing is I'm getting different numbers (bit rates) with the old version vs the newer ones.

with the old version I'm getting 9555. with the new version a soon as I drag it in it says 9555 for split second and then begins the "process" and when it's done the number says 1977!! way different.

I tried it with a different DVD and the numbers were different but very close to each other. oh yea it doesn't matter whether the codecs are installed or not. they aren't by default in 2.5 but one in the other versions.


here are some screen shots

with 2.5



same one with 2.7




now the other dvd. close but slightly different





what would cause the difference from 9555 to 1977?? what the hell is going on??

[datdork]

downloaded AVIcodec_1.2_b113 and it list the bite rate as 9554.


the show is 103 mins long with ac3 256 audio. the folder is 1.65 gb. does this sound right??

[DanielG]

Originally Posted by datdork

the show is 103 mins long with ac3 256 audio. the folder is 1.65 gb. does this sound right??

Ugh. That's some serious compression right there... If the full 103 minute show is 1.65 gigabytes in size, then an average bitrate of 1977 kbit/sec sounds about right.

[datdork]

Originally Posted by DanielG

Ugh. That's some serious compression right there... If the full 103 minute show is 1.65 gigabytes in size, then an average bitrate of 1977 kbit/sec sounds about right.

that's what I was afraid of. footage looks great and was done by one of the less than faces guys.

still wonder why I'm getting two different numbers and why the other program reads 9554. oh well.

[DanielG]

Originally Posted by datdork

still wonder why I'm getting two different numbers and why the other program reads 9554. oh well.

I had a closer look at your screen shots and it looks like you are opening different VOB files in your two versions of GSpot. That may be causing the discrepancy (ie. menus may be encoded at a different bitrate to the actual concert). Choose the largest VOB file (should be around 1 gigabyte in size) and check the bitrate on that...

[datdork]

did it again to be sure and same thing happened. with 2.52 it says 9555 and with 2.6 & 2.7 it said 1977.

[U2Lynne]

I was thinking about this last night.... I'm a Mac user, not a PC user, but we have discussed video stats in Staff before. One thing I seem to recall from our discussion is that GSpot (who thought of that name anyway?) calculated the maximum bitrate for the VOB, not the average variable bitrate. It sounds to me like the newer versions (2.6 and up) are now calculating the average VBR. Normally, the two numbers would not be significantly different. A DVD author would set what he wants the average to be and then give it a range... like 7000 kbps +/- 1000 kbps. So, if you used a version of GSpot prior to v2.6, you would get 8000 kbps, whereas the newer version would give you 7000 kbps. But, it sounds like on some of these DVDs you are looking at, the author did not bother with giving it a range, and so the max is clear up there, whereas the average VBR is very low.

I'm just guessing here, but it makes sense to me. Meanwhile, I'm flagging this post for our VBT Mods in the hopes that they know what is going on.

[gsmyth79]

That might be a setting you can change now or something, to do max or avg. Good call Lynne. But that raises the question (if this is true), are all the older bitrate readings from v2.5 and previous not as meaningful (avg BR is a much more informative statistic IMO)?

There's a Mac program that let's you look at the bitrate over time so you can see if there are any huge fluctuations (like would be the case for this disc to give max @9k but avg @1.7k). Not sure if you can do that on a PC. All that being said, this just might be one anomalous disc.



hehhehheh Gspot hehhehheh

[datdork]

thanks for the replys

That might be a setting you can change now or something, to do max or avg. Good call Lynne. But that raises the question (if this is true), are all the older bitrate readings from v2.5 and previous not as meaningful (avg BR is a much more informative statistic IMO)?

I looked around under setting and there isn't much to change. saw nothing about changing max vs vbr.

so it does appear that any bit rate reading done with v2.5 is only the max and not the vbr.

playing the dvd back in powerdvd you can right click > show information. it shows the video around 2mbps and going as low as 1.4 mbps.

I sent a nice email to the author and pointed them to this thread. one guess is that it somehow accidentally got ran through shrink or a similar program. or as lynne pointed out they didn't set the range.

[saltman]

Originally Posted by datdork

the show is 103 mins long with ac3 256 audio. the folder is 1.65 gb. does this sound right??

It sounds like the previous versions are reporting peak bitrate and the new one is reporting average.... 1.65 is about right for a 1977 kbit/sec show at that length. It seems I remember this being the case in older versions (showing peak) but a change is not mentioned in any of their release notes.

[saltman]

Originally Posted by datdork

I sent a nice email to the author and pointed them to this thread. one guess is that it somehow accidentally got ran through shrink or a similar program. or as lynne pointed out they didn't set the range.

The default range in Sony vegas (and Premier Pro and probably any others that use the Mainconcept rendering engine) using the dvd templates is low like that.... It will set the high to be 8200 mid at 6200 and low at something ridiculously low like 1200. Those are not exact numbers but that is the gist of it.

[DanielG]

Originally Posted by gsmyth79

There's a Mac program that let's you look at the bitrate over time so you can see if there are any huge fluctuations (like would be the case for this disc to give max @9k but avg @1.7k). Not sure if you can do that on a PC.

There are a couple of programs on the PC that provide a graphical representation of the bitrate of a video.

One is called "Bitrate Viewer" - you can download it from: http://www.tecoltd.com/bitratev.htm

Also, DVD-Lab (DVD authoring tool) has a built in bitrate viewer as well. Just import one of your VOB files into the program and then one of the menus has an option to analyse the bitrate. You can download DVD-Lab from: http://www.mediachance.com/