Converted video file not the same length!

[MPIII]

Yesterday I was working on a crucial audio / video project. I am mixing 5.1 surround for a DVD using a multitrack audio program called Nuendo. The video editors have given me MPEG2 files of the video. I can play those video files in Nuendo, but Nuendo seems to be more happy with video files that do not have any audio.

So I bought TMPGEnc Plus and De-Multiplexed the MPEG2 so that I have a .m2v file – that has video only. To my horror I discovered (kind of late in the project) that the .m2v and the .mpg files are not the same length ! In other words, when I bring the .mpg file into Nuendo, I see a particular image at exactly 1.00 minute on the time line… when I bring in the .m2v file into Nuendo I see a DIFFERENT image at exactly 1.00 minute on the time line…

I haven’t determined exactly how far off they are, but it is a SUBSTANCIAL amount! (about 6 seconds off after 1 hour of video).

No support at the TMPGEnc site.

If you can shed some light of this situation, I would like to hear it.

[Nic]

Try demuxing with a different program to begin with, (you can even try with ReJig that I wrote ( www.rejig.org )), To see if that helps, but I very much doubt it is a TMPGEnc problem.

Have you tried checking the video frame at a 1.00min interval in another program? I fear that it is Nuendo at fault...

-Nic

[DDogg]

Also, let us know what the source (PAL, NTSC) and framerate of the mpeg2 is. Under certain circumstances NTSC Mpeg2 can use a pulldown flag to signal 29.97 playback for 23.976 video. You did not mention what tool you were using to judge the position at 1 minute. You may see incorrect framecount depending on what playback tools you are using. In other words, the video could be accurate, but the tool used to evaluate frame position may not show accurate results, thus misleading you. This is just a shot in the dark, and may not apply to your situation.

[MPIII]

I am going to do some investigating. I think Nuendo is at fault.

Nuendo does not accept .m2v files, so I fooled the program and changed the file extension to .mpg ( Maybe I fooled myself too...)

Now... I can go through another step with TMPGEnc and create a true .mpg (that doesn't have any audio) by multiplexing the .m2v file with nothing as the audio input to the multiplex. I will try that today. I have noticed that the actual file size of the three are different: .mpg .m2v .mpg(without audio)

:confused:

[Abond]

@MPIII
Well it is understandable about the file sizes. m2v is elementary stream, mpg is system stream audio+video+overhead and mpg(without audio) is system stream containing only video+overhead -> therefore bigger than m2v but smaller than mpg.
My suggestion is to look at the frames and files using VDubMod.

@DDogg
He said he has looking at the frames in Nuendo (never heared about before).