I am working with some video files that were imported from my camcorder (MiniDV). I used Intervideo WinDVR to record camcorder playback on firewire (1394) port. The files are quite large (13 GB). When I play these AVI files on my computer using various players (WMP, PowerDVD, ... etc.) they seem to play OK. I'd like to put these on DVD so I encoded some of these files using MainConcept MPEGEncoder (AVI to MPG). The encoded MPG files compressed to 2.8 Gb. When I play the encoded MPG files back the video and audio are out of sync. I tried changing various MPEG Encoder settings like "type" (DVD, MPEG2) and "audio mode" (LPCM, Mpeg1/2). I set the "size" (720x480) and "frame size" (29.97) the same as the input file and got the same result. I tried using SUPER encoder and obtained the same results. I don't do this a lot but I haven't had this trouble with smaller video files in the past. I'm pretty sure I haven't changed the codecs. What am I doing wrong?
Is this a constant sync issue where the sync outage is the same throughout or where it gradually goes out of sync? AviMux_Gui should fix a constant sync whereas VirtualDubMod may fix a gradual sync issue. Download AviMux_Gui (Binary 1.7.8): http://www.alexander-noe.com/video/amg/#download open your avi in it, highlight it and select generate data. Now, in the lower window, highlight audio and if the number that appear's to the right is greater than 0, select start, name and put the file as you wish and use it to encode. For a gradual issue, open the avi in g-spot and check the audio. There is a good chance that the audio has been encoded with VBR MP3, which seems to cause sync issues with a lot of encoders. If this is the case, open the avi in virtualdubmod (click OK to the VBR warning you will get), then go Streams->Stream List. Right click on the audio and select Full Processing. Right-click again and select Compression. Choose Uncompressed PCM. Click OK, then click Save WAV and create new file. Once this completes, click on Add, and select your wav file. Click on the MP3 audio track, then click on the disable button. Click OK, then go File->Save as. Make sure it is set to Direct Stream Copy, and save a new avi file with just your new audio track. Finally, open this new avi file, and test it for audio sync. If everything is good, use this in MC and see how it goes. (saw this about VirtualDubMod on another Forum) If it isn't VBR MP3 audio, you have something else to worry about. Btw, avi usually play's fine on a pc even when they encode badly so I alway's check mine first in AviMux_Gui and make a wav. Also, the Bitrate can be adjusted to around 4200-4300 MB unless there is some reason for 2.8
I haven't determined if the sync problem is constant or variable. I am trying to characterize this problem. In doing this I have conducted a little test. The 13 GB AVI files are the result of importing the data from MiniDV tapes that are 1 hour in length. The AVI videos are high quality. For my test I imported approximately 10 minutes of a 60 minute tape. The result of the import is a 2.1 GB AVI file (about 1/6th the size of the 60 min. tape). Encoding this video in Main Concept with the same parameters as before resulted in audio and video that appears to be nearly in sync. This test implies that the larger the AVI file the greater the sync problem. It would be nice if I could isolate the sync problem to a parameter setting in the encoder. Thus eliminating a step of having re-sync the audio and video. You mention that the audio may have been encoded with VBR MP3. If this is the case, perhaps I can change this setting in the endcoder. What audio settings do you recommend? If I must re-sync the audio and video, I will try your suggestions. For editing videos I currently use MPEG Video Wizard. I think this application may have the ability to adjust the audio track to sync with the video if the sync problem is constant. Perhaps I can use my application for a constant sync problem.
Using GSpot, how will I know if the audio track is encoded with VBR MP3? I haven't used GSpot yet but I have seen an image of the main dialog. In the audio section there are two objects labeled CBR and VBR. I assume the VBR text will be highlighted to show it is active. What about MP3? How will I know if the audio track is encoded with MP3?
According to the DV faq, the source audio should be uncompressed PCM. Why don't you spin off the audio as a separate file and include this as input to the mpeg encoder.
The default audio Bitrate is 224 in MainConcept, I think, and is fine, never used any other setting's. The audio info should show in the lower left of Gspot and running the avi through AviMux_Gui (free) will show you whether it's a constant or gradual sync issue in about 30 second's, 0 if it's gradual, the sync outage in MS if it's constant where upon you can make a new file in less than 2 minutes. As stated, you could make a wav file and use that for the audio in MainConcept but not sure if that will help, here's a guide anyway for VirtualDub (free): http://www.videohelp.com/oldguides/virtualdubaudio
After loading the AVI file into GSpot, the container section listed some interesting information (I'm not currently at home so I'm listing the information from memory). It listed something like "7.5 GB of unused data at end of file". The container also listed that the video was "DV Type 1" (I think). There was more ctitical info in the container section but I can't remember all of it. The audio section revealed little information. There was no data in the Codec and Info fields. The Stat field listed "Codecs installed". The video section listed the codec as something like "dvsd". I'm not really sure about this. The bottom line is the program that I used to transfer the video did a poor job. I've decided to use a different program to transfer the video from MiniDV to my computer. I downloaded and tried WinDV on a couple of shorter length MiniDV tapes. This is a very simple program that, initially, seems to meet my needs.
