Changed frame rate avi to mp4, now time is incorrect...

[Lezleefeetsgoddess]

Ok, let's start a fresh thread, since I already have mosta the job done.
I have an avi file, around 2.5 GB, 4hours an 54 minutes long. 29.97 fps.
I wanna convert it to mp4, ta play on my cellphone.
I'd like to lower the framerate to 24 fps, but when I do that, the resulting mp4 file says it's now 6 hours and 3 minutes long, which is incorrect, right?
How can I, either fix the time on the mp4, or just convert it again and have the time come out correct?
I have handbrake, should I do it with that?
I used ojo total video converter ta make the file I made that has the time incorrect...
Thanks,
Lezlee

[Baldrick]

Why change the framerate? It's not worth the trouble.

[jagabo]

If you changed the frame rate by simply writing a new frame rate value in the header, the change in running time is about right.

If the video is really 29.97 fps and you convert it to 24 fps via decimation you will get jerky video. If the video is already jerky because every 5th frame is a duplicate, smart decimation will smooth it out.

[Lezleefeetsgoddess]

I changed it in total video converter... Tryin' ta make the file size a lil' smaller... for my phone...
It's not jerky at all an looks great, jus' tryin' ta get the time displayed in the phones player ta be correct...

Sorry I don't know that much about this stuff, is there a way to modify the header information for the file and would that fix the problem?

How would I do that?

[Selur]

playtime = 'frame count' / 'frame rate'
-> if you want to lower the frame rate and keep the same playtime you also need to drop frames. So far you just lowered the frame rate, which in turn lengthened the playtime. (it does not matter if the frame rate is lowering by either reencoding the file and changing setting a new frame rate or simply changing the appropriate flags in the container, unless frames get also dropped, lowering the frame rate without loosing frames will lengthen the playback time)

No clue about either Total Video Converter or Handbrake. I know mencoder can do it, since Hybrid uses it to do such stuff.

In Hybrid I would do such a conversion the following way:
1. start Hybrid
2. set Main->Audio handling to 'Passthrough all', this way the audio will not be changed but only remuxed (since the playtime should not change, the audio should stay sync)
3. configure x264 (in the x264-tab in such a way that it will output the file size I require for the output)
4. enable Filtering->Speed change->Speed Settings->Scale output frame rate and select my desired target frame rate
5. set the output (Main->Output File)
5. add the job to the job queue by pressing Main->Add to Queue
6. start the processing by pressing Main->Start Queue
7. wait till the conversion is done

Dropping frame will normally cause jerky motion (since motion information gets lost), but such jerky motion is normally less visible on small displays, so you will probably be fine.

Cu Selur

[Lezleefeetsgoddess]

So if I lowered the framerate and the time came out like an hour longer, but the audio is still only a few seconds off, does that mean total video converter did drop frames?

[Selur]

or it couldn't decode some frames or it's just not got at changing frame rates,.. or the input is vfr or audio and video already a have different length in the input file,...

[hello_hello]

When all else fails...... ie. I can't fix the audio sync no matter what I do with AVISynth and frame rates..... I use AnyVideoConverter (there's a free version). Change the audio sync setting to "default" and go into options and wind the audio sync setting up to maximum. I don't really know what AnyVideoConverter does to be clever but so far I don't think it's let me down. Usually AnyVideoConverter will get the frame rate correct if you leave it on "auto" but you can select the desired frame rate if need be.

AnyVideoConverter will convert to and from lots of different formats so you can probably convert directly to the desired output format. In my case I generally convert to lossless video and audio in an AVI (huffyuv and PCM) and then convert the AVI to the desired final format with my usual program (MeGUI or AutoGK). Converting to lossless first isn't overly time consuming but it does take up a bit of hard drive space (something like 30GB for a movie). You might have to convert the lossless AVI via DirectShow. ffdshow will decode it.

PS. If you change the frame rate using AnyVideoConverter it won't change the duration, it'll drop/add frames if necessary to keep the same duration, so if you set the frame rate manually you might want to check the encoded video isn't juddery.

[Lezleefeetsgoddess]

ok, I'm downloadin' avc now, luv this site... you guys are sooo helpful...
The file was originally in mkv format, butt I converted it ta avi using virtualdub, an I did see some warning about vbr audio, but I did the full processing mode for video and audio, so I think it fixed the audio to cbr in the output avi file? I think ? lol... I had ta do that ta boost the audio by like 22 db...

Kisses,
Lezlee