encoded m2v has less run length ?

[Movie-Maker]

I convert my captured AVI files from my minidv camcorder to .m2v using HCenc, and the run length of the resulting m2v is always displayed somewhat less than the AVI!

For example, when I play the AVI in Windows Media Player it shows a run length of 10:32 but when I play the encoded .m2v it shows me a run length of 9:08! Why is that ?
I haven't really 'timed' it to see if its just the time length display that is wrong or really the length is short and to see if any parts of the movie are 'M-I-A'!

What do you make of this ? Is that normal ?
Even if just the run lenght was being calculated/displayed incorrectly, why could that be so ?
Did I miss something while encoding ??

any help appreciated! thanks!

[poisondeathray]

Did you use the same framerate in your script?

What does mediainfo say about the duration of both files?

[manono]

Why is that ?

Because players don't show the proper length for MPV/M2V/VOB.

I haven't really 'timed' it to see if its just the time length display that is wrong or really the length is short and to see if any parts of the movie are 'M-I-A'!

Assuming the script was good and the framerate is correct (see poisondeathray's post), it's all there. I'd go ahead and author and then complain if it doesn't come out right when all finished.

[AlanHK]

I haven't really 'timed' it to see if its just the time length display that is wrong or really the length is short and to see if any parts of the movie are 'M-I-A'!

Time it.
or use GSpot.

Many player apps display inaccurate times for m2v files. Once you mux in the audio to make mpeg, you can generally get a correct reading.

I use HCEnc and it's pretty reliable. Either it works, or (very rarely) crashes, never had it skip parts of a file.

[Movie-Maker]

I have not directly messed with the framerate at all. All that the avs script has is Avisource and Convertoyv12.
didn't think about running mediainfo or gspot on it, I will try that tonight. hopefully those pull accurate run length unlike the players.

[manono]

If, for example, the AVI framerate is 25fps and you set HCEnc to encode for 23.976fps, then you've messed with the framerate.

All that the avs script has is Avisource and Convertoyv12.

If an AVI, it's most likely already YV12. You can either add Info() to the script (before the Convert line) and open it in VDub(Mod) to check, or remove the convert line from the script and try and open it in HCEnc. It'll reject it if it's not YV12.

[Movie-Maker]

I remember HCenc rejected the file when I tried the first time, and thats what lead to adding the convertoyv12.

I didn't see any option in HCenc (in the gui atleast) to manually set the framerate of the output file.

But anyway, I checked the file with Gspot and everything checks out fine on the m2v. The number of frames and the run length match between the avi and the m2v!

[AlanHK]

If, for example, the AVI framerate is 25fps and you set HCEnc to encode for 23.976fps, then you've messed with the framerate.

HCEnc can't change frame rates. It can apply pulldown, but will only do that if the rate is 23.976. I use it with pulldown default on, if the video is 25fps it has no effect.

To change fps you have to explicitly do so in the Avisynth script.

[manono]

You're right, sorry. Been using CCE too much.