Joining avis with different bitrates

[headless chicken]

I have two avi files I would like to join together, and then resplit (into 3 files of equal length). However, I believe these files may have different bitrates.

1. How do I check if these files do in fact have different bitrates?
2. If they do, is there anyway to join them?

I eventually plan on converting them to SVCD and then placing the trick VCD header on them. Would it be better to first convert the files to MPEG and then join them?

[daamon]

Hi headless chicken,

1. How do I check if these files do in fact have different bitrates?

Use GSpot.

2. If they do, is there anyway to join them?

VirtualDub will join your AVI's I believe - but not sure if it'll do it for different bitrates. If it does, you may still be setting yourself up for problems - not sure. Having never needed to resample the bitrate of an AVI, don't know what tools exist (if any) to do it.

Hope that helps...

[BillyB]

There's a few ways to find out what the bitrate is. What I normally do is open a file in Virtualdub and choose File->File Information and it'll tell you almost everything about the file including the framerate. Write down the framerate of the first file.

It is possible to make a small change in the framerate if it's only by a hundredth of a second or something small like that. Again in Virtualdub, you can choose Video->Framerate and select the Change to option and manually type it in. Then do a direct stream copy of both the video and audio to a new AVI file. DO NOT overwrite your original file, just in case this doesn't work out. Then open your first AVI, then choose the File->Append AVI segment then do a direct stream copy of each segment you want to create.

I know this sounds like it's going to cause problems, but I used to do for some of the video I captured with an old card and it worked fine.

[huntingtheasphyx]

Have a look here

http://www.divx-digest.com/software/index2.html#cutjoin

there are many tools which claim to even join low and fast motion DivX files (old 3.11 divx) so I'm sure there will be something that will work for you if all else fails.


Probably the easiest thing to do though is to convert them seperately to Mpeg with TMPGEnc, get 2 Mpegs, join 'em with TMPEGEnc and then split them to your hearts desire with TMPGEnc. So all you need is the one tool you should already have. Wow that was easy.

[daamon]

Probably the easiest thing to do though is to convert them seperately to Mpeg with TMPGEnc, get 2 Mpegs, join 'em with TMPEGEnc and then split them to your hearts desire with TMPGEnc. So all you need is the one tool you should already have. Wow that was easy.

Joining mpeg2's might be one thing, but I've seen quite a few mentions of audio out of synch with video when mucking around with mpeg2's (there's a prog called Womble, not sure where to get it from, that a few have said it work's OK) - Give it a go (I've never needed to try it). If it works, then sweet. If it doesn't, don't be surprised as editing mpg's has a reputation...

[ZippyP.]

Usually the problem with joining 2 part avi's is that the audio is VBR so Vdub complains that the audio has different bitrates. One solution is to convert the audio to wav, that way the audio is the same. Rip the audio using Goldwave or Vdub. Put the audio back into each avi using the wav audio command in Vdub and save each part using direct stream copy for the video. Join the files by loading the first avi back in Vdub, append avi to get the second part then start the frameserver (or save an intermediate file). Look in the Edit section (over there <-<-) for a frameserving guide. Use the source range function in TMPGEnc and the batch encode feature to make your 3 mpegs from the framserved source file.

Hope that helps.

[duhmez]

Use Nandub to join vbr avi's. It works with VBR mp3 too so all is good.

Dont forget to direct stream copy.

[dcsos]

This is where, I think, you'll really see advantages to using a NON-LINEAR EDIT program instead of a TRANSCODING APPLIANCE
Premiere, Vegas, Ulead

the thing about timeline editors is you can set properties for individual teratment to each clip and the program adjusts the bitrates, frame sizes, etc. to one output standard you choose

[spectroelectro]

Yes, quite right, the only truly reliable way to join different types of AVIs is to feed them into an NLE program and write the output to yet another AVI. ALso, if you're trying to join DiVX files you might want to convert 'em to another format before doing so, since the varying rates of the 2 DiVX files could cause problems, or your NLE program might not be able to import 'em.
You could convert your 2 DiVX files to DV format AVI files (easy enough with VDub or TMPGenc) or to MPEG-2 files. IN the case of MPEG-2 files, you can edit and join these using the superb program Womble MPEG VCR. I've edited and joined many a group of MPEG-2 files and never had any sync problems yet courtesy of Womble. It's by far the best piece of software for editing MPEG-2 files.

[headless chicken]

Thanks for the feedback everyone. I'm still confused as to the best method of approach since a wide variety of solutions and programs have been recommended. Both my files have the same video frame rate (and are Divx4), but I was thinking they would have different bitrates due to audio/video length.

Here is the file info from VirtualDub. As you can see, the video data rate for the two files are different.

[huntingtheasphyx]

That isnt a problem. Just join them with virtualdub, then convert them to Mpeg2 for your SVCD.

To join in virtual dub, open the first file as you have done already, then go to File, Append avi Segment, then choose the 2nd file.

Go to the Audio and Video menus and select "Direct Stream Copy" for both.

Now save the file with a new file name and you've joined them.

Then convert to Mpeg2 with one of the methods mentioned.

If there are any problems doing any of this, virtualdub will tell you straight away. But I cannot see any problem.

If you dont try, you will never know!

[Gazorgan]

You AVI bitrate doesn't mean anything.

To join AVI's in VDUB, they have to have:

1) Exactly the same framerate
2) The same Video codec (as well as the same 4cc header)
3) The same Audio Codec
4) The same Audio sample rate (this is usually the killer)
5) No VBR Audio since VDUB doesn't deal with it

That's it. You can usually convert the audio to CBR mp3 in little time with no Video re-encoding.

[duhmez]

nndub supports vbr mp3, as does virtualdubmp3

the fourcc and codec must be the same as well as the framerate.

Using a nonlinear editor to join them would be foolish if these conditions are met.

If they dont match, by all mean use an nle and save out as huffyuv afore final encoding, or join them with avisynth and encode your avs file.