two files of same movie, keep audio from one and video from the other?

[popque]

Hi.
I have two files with the same movie.
one has the correct audio track, the other has good video.
Now I would like to append the audio track to the good video but do not understand what I do wrong.
I have used handbrake to set constant frame rate to 29.97fps on both. used vlc to extract sound to flac and import sound as mp3. Then used avidemux to set the audio sync correctly at one point in the beginning. When I scroll the video to a point at the end the sound is totally off sync.
The video file is a mkv and the sound comes from an avi file if it could be a problem?
Suggestions?

[JVRaines]

Is the video exactly the same length in both files?

[johnmeyer]

1. Trim them both to the same length.
2. Demux both (i.e., separate the audio and video).
3. Re-mux, using the good audio and good video.

If you do it correctly, the good audio and good video should be identical to the originals.

BTW, if you don't have software that lets you do frame-accurate, no-recompression cuts (except for a few frames at the cut point), like VideoRedo, then an alternative is to NOT cut the video, but only cut the good audio so that it matches the good video (i.e., same in/out points). You can pad the audio with silence at the beginning and/or ending, in order to get it to match the video.

It is much easier to find software that can cut audio without re-encoding than it is to find software that will do that same thing with video.

[netmask56]

Post a MediaInfo report (text mode) of both files then we can see the differences. Another quick thing you could do, simply extract the audio from the AVI and add it to the MKV file using MKVMergeGui - no ree-encoding involved and only takes minutes. You will then have a MKV with both audio tracks and you can switch between them to hear the differences in timing if any...

[popque]

They are different length.
sound is 1:54 and video is 1:59
I have a couple of questions about it all if you could bear with me.

1)How do I manage the audio: If I'm going to fill in with silence, what is a good job procedure to do it?
2)I'm puzzled. Can I just extract the sound from a video file and put it in an other video file without making them the same frame rate? Are not the sound attached to the frames? the frames are like ques for the audio or how does it work?
3) I thought that I just could add a audio track and then transpose it to the right time and then since it comes from the same fps movie it would progress the same speed and I would not get this problem. the part that would be missing would just be quiet.
4) Lastly, How does the FPS of the Audio work? I notice that it is totally different from the fps of the video.

I uploaded the mediainfo files

[sneaker]

When people talk about "fps" in relation to audio they usually mean the audio is synced to a video of said "fps" value. Since both your files have a video fps of 23.976 I'd normally say you don't have to change audio speed. But the durations 119 minutes to 114 minutes seem to match a typical PAL speedup (factor 23.976 to 25). But sometimes these differences can also be a result of different cuts (e.g. cinema cut vs director's cut, though I don't believe that exists for Howl's Moving Castle) or maybe removal of ending credits to save space.

First test:
Open both files in MKVToolNixGUI, un-tick any tracks you don't need and click "Start Muxing". Are video and audio synced? If not, try to find the audio delay and do the muxing again (in the MKVToolNixGUI's "delay" field of the audio track). Is the sync now perfect for the whole movie or does it go out sync progressively? If it's the latter you may need to change to speed. In MKVToolNixGUI's "fps" field of the video track choose "25p" and do everything again (delay may need to be adjusted again). Alternatively you can recode the audio with speedchange.

[popque]

Thanks for the hint about the PAL speedup factor. The audio track was originally 25fps. I used handbrake to change it to 23.976. Should that not have canceled the Pal speedup factor?
I will try MKVToolNixGUI.

[sneaker]

HandBrake does not change audio speed. The only thing you did was botching the video track.

[popque]

So if I'm doing this operation (moving audio track from one video to another) from time to time and want to learn a good workflow, minimal effort and quality yield.
Do you have a suggestion on workflow and program to use?
The program does not have to be a freeware.
I will not just work with mkv but mk4, avi and so on.
Also if I want to understand things like bitrate, muxer, fps in audio tracks, containers and so on. is there a book or a good guide on the internet to read up on the foundation?

Thanks

[popque]

I ended up using avidemux to extract the audio, then using MeGUI to make the sound slower, then appended it to the video using avidemux.
Lastly shift it using avidemux.
All worked out great