Strange muxing...decrease in overhead? (vc1 + wma)

[Furiousflea]

Bit of a weird one here.

1. I've ripped a HD DVD movie only to WMV format so I've got a final output size of around 6.9GB and an encoded 5.1 track in WMA Pro 10 format of around 1GB so the total of the 2 files is 7.9GB (this is oversized considering I need to mux the 2 streams and the overhead produces a larger file than a DL DVD+R can hold)

2. I mux the 2 streams with "Windows Media Stream Editior" and produce and output file of 7.97GB

3. I load the file in Boilsoft WMV\AVI splitter to trim of 20mb so it will fit on a DL disc (chop off about 20 seconds of the last logos that come up after the credits)

4. The resulting file is 7.87GB!!! :eek:

This confuses me a lot, would this be because Expression Encoder is already outputting a file in a WMV container and thus when the Boilsoft WMV\AVI splitter is trimming the last 20 seconds or so of video it is removing all that extra container info....

Would that mean that Windows Media Stream Editor isn't doing its job properly? So I am carrying the overhead of the original encoded WMV along with it + the overhead of muxing the 2 audio\video streams?

Very confused!!! I've watched the resulting WMV on my Xbox 360 with no issues at all and even repeated the process to make sure nothing was going wrong...

Should I be concerned\What's happening here?

Many thanks for any help clearing up this puzzle.

[Guest]

3. I load the file in Boilsoft WMV\AVI splitter to trim of 20mb How do you know it cut off only 20mb?

[Furiousflea]

I was making a rough guess, it was about 20 seconds.

I tried again but not cutting off anything at all and it produced an output of 7.9GB (The exact size of the 2 files combined before muxing)

I get the feeling this is normal and that the Boilsoft program is just trimming the fat that doesn't need to be there that gets added by Window Media Stream Editior?

If the 2 streams that I'm muxing are already in the wmv container and total "x" muxing them together should still produce an output of size "x" right? Windows Media Stream Editior seems to be adding on more overhead that doesn't need to be there?

I'm clutching at straws here as you might be able to tell :confused:

[benwaggoner]

If the 2 streams that I'm muxing are already in the wmv container and total "x" muxing them together should still produce an output of size "x" right? Windows Media Stream Editior seems to be adding on more overhead that doesn't need to be there?
At higher bitrates, ASF mux overhead is typically around 9-13 Kbps. Would that be enough to count for this change?

[Furiousflea]

At higher bitrates, ASF mux overhead is typically around 9-13 Kbps. Would that be enough to count for this change?

Thanks for the response Ben.