Delay in muxing audio stream?

[architectofpain]

Hello.
I have two different avi files of the same film (two different vhsrips of an otherwise unavailable film). One of the files features better quality video, but it has mp3 audio. Conversely, the lesser quality video file has ac3 audio. What I'd like to do (and have been trying to do) is mux the better quality video with the ac3 track. However the 2 video files have a 2 second difference. Is it possible to sync them both (adding some sort of delay until the video track begins) and then mux them together?

Thanks.

[Wolfen]

Yah, Just demux the sound off the avis with virtualdub, Save somewhere you remember and mux the sound back to them, which ever one you want. There is a preview and time setting to sync the audio.

[architectofpain]

I'll give that a go. Is there anywhere that will show me the exact timing (including milliseconds) so that I can mux it perfectly?

Thanks!

[Wolfen]

To tell you the truth I've never had to sync audio but I know it can be done with virtualdub it can pretty well do almost anything to video. I know in the preview it has the frame by frame view. But anyway just ask around here, there is always help here for anything to do with video.

[architectofpain]

I'll keep at it. Might be worth comparing the times and adding silence in Audacity to make up the difference.

[architectofpain]

Had a go at it, I got it to sync (with virtualdub) at the start but it seemed to drop out of sync at various points in the film. I'll have to find another method.

[Safesurfer]

Maybe try Syncview.

[architectofpain]

Will give it a go, thank you.

[AlanHK]

I have two different avi files of the same film (two different vhsrips of an otherwise unavailable film). One of the files features better quality video, but it has mp3 audio.

The AC3 is not necessarily better quality, especially if both are from VHS.
Look at the audio rate.
If you do a blind trial, can you really tell the difference?
And if you edit the audio, it will be decoded and reencoded, so the original format won't matter.
(Except if you use Delaycut, which can cut AC3 or add a delay losslessly.)

A fuzzy source encoded at a high rate is still fuzzy.

If there is static or hum, you might import into Audacity.
The latest version has a much improved noise filter. Also it can use ffmpeg to import and export most formats, including AC3.

[architectofpain]

The audio bitrate of the AC3 file is 256 kbps while the mp3 file is 128 kbps.

I'll try Delaycut, as it seems to be able to do what I am trying to do.

EDIT:

Here are both sets of file information (it seems I may have ripped the ac3 file to 320 kbps, depending on what happens I can just rip it again.) maybe the information will reveal why it didn't sync the first time?

====== INPUT FILE INFO ========================
File is ac3
Bitrate (kbit/s) 320
Act rate (kbit/s) 320.000
File size (bytes) 218063238
Channels mode 2/0: L+R
Sampling Frec 44100
Low Frec Effects LFE: Not present
Duration 01:30:51.580
Frame length (ms) 34.800000
Frames/second 28.735632
Num of frames 156654
Bytes per Frame 1392.0000
Size % Framesize 870
CRC present: YES
=============================================
====== TARGET FILE INFO ======================
Start Frame 0
End Frame 156653
Num of Frames 156654
Duration 01:30:51.559
NotFixedDelay 0.0000
=============================================

====== INPUT FILE INFO ========================
File is mpeg 1 layer 3
Bitrate (kbit/s) 128
Act rate (kbit/s) 128.000
File size (bytes) 87253159
Channels mode Joint Stereo
Sampling Frec 44100
Low Frec Effects LFE: Not present
Duration 01:30:53.322
Frame length (ms) 26.122449
Frames/second 38.281250
Num of frames 208760
Bytes per Frame 417.9592
Size % Framesize 200239
CRC present: NO
=============================================
====== TARGET FILE INFO ======================
Start Frame 0
End Frame 208759
Num of Frames 208760
Duration 01:30:53.322
NotFixedDelay 0.0000
=============================================

Keeping in mind that the video associated with the mp3 file is to be the video source while the ac3 file is to be the audio source.

Thanks.

[AlanHK]

Sampling Frec 44100

DVD has to be sampled at 48000. You're going to have to reencode anyway to do that.
How are you making your "output" AC3?
It probably has a sampling setting.

I may have ripped the ac3 file to 320 kbps,

No point having a higher output rate than your input. Wastes space you could use for improving video rate.

[architectofpain]

Sampling Frec 44100

DVD has to be sampled at 48000. You're going to have to reencode anyway to do that.
How are you making your "output" AC3?
It probably has a sampling setting.

I used AoA Audio Extractor. It has an ac3 setting.

I may have ripped the ac3 file to 320 kbps,

No point having a higher output rate than your input. Wastes space you could use for improving video rate.

Yeah, I know this now. AoA Audio Extractor also allows you to choose the sample rate so I'll rerip the ac3 file to 256 and change the sample rate to 48000.

Thanks.

[architectofpain]

I've been able to solve this, it was just a timing issue. Virtualdub did the trick just fine!