MPEG-2 cutting tool that can find midpoint based on filesize

[DRP]

I want a video cutting tool that can tell me where the midpoint of an MPEG-2 video stream is (in time) based upon the filesizes of the two segments.

For example, in the case of SVCD VBR encoded movies, the midpoint of the movie in filesize does not necessarily correspond to the midpoint of the movie in time. I want to cut the movie so that I end up with two equal sized MPEG-2 files, but I want to know where that point is in terms of the running time. Is there a tool out there that can work this out for me?

[Tommyknocker]

How long is the movie?

[DRP]

The source movie is 145473 frames PAL = 96':58".92

I have encoded it to MPEG-2 for putting on two SVCD discs. The end result of that encoding has given me a filesize of 1,595.8MB which is very close to the 1,600MB I was aiming for (I can overburn the discs I'm going to put it on, so fitting 800MB per CD is not a problem).

Obviously I encoded it using a 2-pass VBR method - min = 0, max = 2500, avg = 2050.

I want to be able to find out where to cut it (using TMPGEnc's MPEG Tools) time-wise to achieve two files of 797.9MB size. Can it be done? What do I use to do this?

[offline]

DV-Tool 0.24ß
a swiss army knife for digital video
by CM of the Muscle Soft Crew

This is what DVtool does:
* truncate, clone, split and merge files, DVD aware
* analyse and backup DVD streams
* calculate video data rates for ripping & capturing
- automatic shutdown on long idle time (currently disabled)
- run user configured (command line) tools (alpha)

http://www.musclesoft.de/~combatman/

[DRP]

Thanks for the suggestion. It does a really crap job of the cutting (no audio at all in the second part) but it does work out what I need it to work out, which is the time point at which when cut the video will be broken into two equal sized files.

I'll continue to do the actual cutting with TMPG MPEG Tools since ultimately it does a much better job and just use DVTool to work out for me where that cut point should be.

It a bit of a round about and time consuming way to do it, but it'll have to do for the time being until a better way comes along.

Thanks again.

[Tommyknocker]

The source movie is 145473 frames PAL = 96':58".92

Half of 96 = 48

Half of 58 = 29

Half of 92 = 46

Answer: 48':29".46

That kind of stuff you can do in your head.

[offline]

really crap job of the cutting (no audio at all in the second part)

Oh.. my copy works fine. Try what I think is
called womble mpeg-2 editor. It is not free but ppl
here seem to swear by it

Here is the link
https://www.videohelp.com/tools?tool=74#comments

[DRP]

The source movie is 145473 frames PAL = 96':58".92

Half of 96 = 48

Half of 58 = 29

Half of 92 = 46

Answer: 48':29".46

That kind of stuff you can do in your head.

You must not have read the bit where I explained how the mid-point of the movie running time does NOT correspond to the mid-point of the movie filesize.

[Tommyknocker]

Remember, headers and padding throw the midpoint off. When you edit at the time midpoint, you edit at the midpoint of the movie. This did not work for you in terms of file size?

[energy80s]

De-mux the file with MPEG Tools in TMPG and re-mux it with bbMPEG. That will allow you to set a split file size point and output two perfect files.

[DRP]

Remember, headers and padding throw the midpoint off. When you edit at the time midpoint, you edit at the midpoint of the movie. This did not work for you in terms of file size?

No. As I said the video is VBR encoded. The first half of the movie contains all the usual expanses of colour and movement for it's entire duration, the second half of the movie contains almost 7 minutes of largely black screen while the credits are rolling. Obviously in this case the second half is going to have a significantly lower demand on bits than the first half to maintain the same quality of picture. This is in fact what I experienced when I split it at the running time mid-point. The first half came in at 811.2MB and the second at 784.6MB. Even with my very best overburning efforts on the discs I have, 811.2MB won't fit.

[DRP]

really crap job of the cutting (no audio at all in the second part)

Oh.. my copy works fine. Try what I think is
called womble mpeg-2 editor. It is not free but ppl
here seem to swear by it

Here is the link
https://www.videohelp.com/tools?tool=74#comments

Thanks for the link, I'll give that a go.

[DRP]

really crap job of the cutting (no audio at all in the second part)

Oh.. my copy works fine. Try what I think is
called womble mpeg-2 editor. It is not free but ppl
here seem to swear by it

Here is the link
https://www.videohelp.com/tools?tool=74#comments

Thanks for this recommendation to try Womble. It is proving to be quite useful for my cutting and joining MPEG requirements. I am however still mystified as to how I can use this program to do what I have been describing here in this thread. Do you know how to make it do what I want as described here?

[DRP]

Does anyone know of a tool or method to do exactly as described above but for cutting a video into thirds instead of halves?

DV-tool works quite well for finding the midpoint of a video, but falls down somewhat when wanting to find thirds. It is not possible to select exactly the two points where three equal sized streams will be the result. Is there a tool out there which will allow this to be done?

[johns0]

De-mux the file with MPEG Tools in TMPG and re-mux it with bbMPEG. That will allow you to set a split file size point and output two perfect files.

Do that to get 3 files.

[DRP]

De-mux the file with MPEG Tools in TMPG and re-mux it with bbMPEG. That will allow you to set a split file size point and output two perfect files.

Do that to get 3 files.

Okay, thanks. I'm giving this a try now. I've read the guides on it for cutting but neither of them seems to fit exactly what I want to do. Do I just set the start point at 0 sec and the end point at 999999999 sec and then specify the max MB size I want? Will doing that make bbMPEG cut it at the appropriate locations?

[DRP]

Tried bbMPEG and program is crap - no better than DVtool in fact. Result is almost the same. Program crashed at the end of the second part and the beginning of the third part.

The one segment it managed to supposedly successfully create had audio only part of way in meaning that the size/length was wildly inaccurate anyway.

Looks like I'm back to trial & error testing with TMPGEnc instead to narrow in on the ideal cut points. Funny that there isn't one functional tool out there that can do this reliably.

[energy80s]

Odd that, as bbMPEG is the best muxer out there. Are you sure your MPEG file isn't badly encoded / corrupted??

[johns0]

Ive used bbmeg lots of times with no errors cutting files,only time i get errors is with stream errors and wrong settings.

[DRP]

Odd that, as bbMPEG is the best muxer out there. Are you sure your MPEG file isn't badly encoded / corrupted??

Pretty sure yes. It was made using TMPGEnc from the DVD vobs I ripped myself from the DVD. I did nothing unusual in the MPEG encoding in TMPGEnc, just the same procedure I always use and have had great success with for a long time.

[Ripper2860]

Take a look at Easy Video Splitter. Does the job for me and seems to provide exactly what you want.