video bitrate

[natty]

is there a way to change video bitrate on movies as I have these 2 halfs of a movie which I am going to join in VirtualDub 1st 1/2 says 1431 kb/s and 2nd 1/2 says 1063 kb/s and the Qf in gspot on 1st 1/2 says 0.304 bits/pixel and on 2nd 1/2 Qf says 0.255 bits/pixel

[jimmalenko]

You could by re-encoding one section to match the other. But if your end goal is DVD you may be better off just encoding each to DVD specs seperately. If your end goal is to retain whatever format they're in, then virtualdub won't be able to help without re-encoding.

[natty]

I was told b4 u can join 2 1/2`s of a movie the bitrates have to be the same. so u saying just convert to vobs the join that way

[guns1inger]

If you convert both halves seperately, you can them import them into tmpgenc DVD author, into the same track (title), remove the chapter point TDA automatically inserts at the start of the second half, and you should get a single, seamless title.

[jimmalenko]

I was told b4 u can join 2 1/2`s of a movie the bitrates have to be the same.

For virtualdub to join them, yes. Other tools may or may not require the bitrates to be the same.

so u saying just convert to vobs the join that way

If your target is DVD, then I would convert to DVD-compliant MPEGs, then use my authoring software to join on the fly.

However, if your encoding software of choice authors as well (it outputs as VOBs), then you can join them (reauthor) with any authoring software that accepts VOBs as input.

[guns1inger]

Not all authoring software will create seamless titles from mixed sets, or give you total freedom to chapter etc as you please. TDA has been shown to do this.

[natty]

remove the chapter point TDA automatically inserts at the start of the second half,

where do you do this on TDA

[jimmalenko]

on older versions (v1.6 and previous) go to your second clip, press Edit and go to the chapter cut edit tab.

[manono]

natty wrote:
I was told b4 u can join 2 1/2`s of a movie the bitrates have to be the same.

For virtualdub to join them, yes. Other tools may or may not require the bitrates to be the same.

The video bitrates don't have to be the same. Think about it. If the AVIs are 2 parts of the same movie, but split into 2 CDs, don't you think, 1) the bitrates of the 2 halves will be different, and, 2) they can easily be joined back together again?

And if encoded properly using VBR encoding, the 2 halves will have different bitrates, as the complexity of the scenes won't be constant throughout the movie. Ordinarily the 2nd half has the higher bitrate, but natty has one where the first half's is higher. I'm assuming here that these are 2 halves of the same movie encoded at the same time. Have you even tried to join them, natty?

[natty]

And if encoded properly using VBR encoding, the 2 halves will have different bitrates, as the complexity of the scenes won't be constant throughout the movie. Ordinarily the 2nd half has the higher bitrate, but natty has one where the first half's is higher. I'm assuming here that these are 2 halves of the same movie encoded at the same time. Have you even tried to join them, natty?

no I have not tried to join them yet as like I said earlier the 2 1/2`s have different video bitrates

but i am going to convert them both to vobs using convertxtodvd then use TDA like guns1inger said and see how it go

[gadgetguy]

...
The video bitrates don't have to be the same. Think about it. If the AVIs are 2 parts of the same movie, but split into 2 CDs, don't you think, 1) the bitrates of the 2 halves will be different, and, 2) they can easily be joined back together again?

And if encoded properly using VBR encoding, the 2 halves will have different bitrates, as the complexity of the scenes won't be constant throughout the movie. Ordinarily the 2nd half has the higher bitrate, but natty has one where the first half's is higher. I'm assuming here that these are 2 halves of the same movie encoded at the same time. Have you even tried to join them, natty?

Don't have to think about it, I've tried it (and retried with each new release.) VirtualDub(et.al.) will not accept the second clip if the bitrate, (or average bitrate for VBR) is not the same. If there was a way to split a movie into two parts while maintaining the same reported bitrate, then they would easily fit back together with Vdub.

[jagabo]

I use VirtualDub, VirtualDubMPEG2, and VirtualDubMod to join AVI files of different video bitrates all the time. It doesn't matter if they are CBR with different bitrates, VBR with different average bitrates, or a mix of CBR and VBR. Other parameters, like frame size, frame rate, video codec, and audio codec must be the same.

[manono]

Hi-

VirtualDub(et.al.) will not accept the second clip if the bitrate, (or average bitrate for VBR) is not the same.

Simply not true. I just got done checking out maybe 15 different movies on AVI divided into 2 parts, 2 or 3 downloaded, but mostly my own. When I make movies for 2 CDs, I generally use the AC3 audio. Every single one with AC3 audio, bar none, joined with no problem. After checking out 4 carefully, putting on the hard drive and then appending using VDubMod, I stopped testing AVIs (XviDs almost entirely, with a couple of old DivX 3.11) with AC3.

Then I started looking for AVIs with MP3 audio, and the results got more interesting. I make all my MP3 audio using VBR. About half wouldn't join, not because of different bitrates for the video, but because of audio VBR MP3 mismatches between the halves. 2 had 2 audio tracks, a soundtrack and a commentary track, and they wouldn't join. A couple of more wouldn't join because of a slight difference between the audio bitrates. The ones with the same audio bitrates for the 2 halves joined with no problems. Just for fun I took one that wouldn't join and stripped out the audio, and the audioless videos joined with no problem. So, to join 2 halves where the VBR MP3 audio has slightly different bitrates, It'll have to be converted to WAV audio and reencoded as CBR, I guess, or maybe ABR, if that will assure they have the same bitrates for both halves.

Conclusion: My original assertion that "The video bitrates don't have to be the same." is correct. If you make the movie and then split it, it's perfectly OK for the 2 halves to have different video bitrates. I was surprised however, to find some problems joining AVIs that used VBR MP3. But like I said, most of my 2-part movies on AVI use the original AC3 audio, and with them there's never a problem.
Part 1

Part 2

Joined