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Posted

So, I've got two rather large .avi files that I need to join, then convert to a format (vcd?) that can play in an everyday dvd player. Any help, pointers, step-by-step walkthrough? :aiee:"

"Of course the people don't want war. But after all, it's the leaders of the country who determine the policy, and it's always a simple matter to drag the people along whether it's a democracy, a fascist dictatorship, or a parliament, or a communist dictatorship. Voice or no voice, the people can always be brought to the bidding of the leaders. That is easy. All you have to do is tell them they are being attacked, and denounce the pacifists for lack of patriotism, and exposing the country to greater danger."

 

- Herman Goering at the Nuremberg trials

 

"I have also been slowly coming to the realisation that knowledge and happiness are not necessarily coincident, and quite often mutually exclusive" - meta

Posted
Windows Movie Maker is incredibly easy to use and comes with XP SP2.

 

I've combined movies with that before, but they always turn out lower quality or super large filesize.

"Of course the people don't want war. But after all, it's the leaders of the country who determine the policy, and it's always a simple matter to drag the people along whether it's a democracy, a fascist dictatorship, or a parliament, or a communist dictatorship. Voice or no voice, the people can always be brought to the bidding of the leaders. That is easy. All you have to do is tell them they are being attacked, and denounce the pacifists for lack of patriotism, and exposing the country to greater danger."

 

- Herman Goering at the Nuremberg trials

 

"I have also been slowly coming to the realisation that knowledge and happiness are not necessarily coincident, and quite often mutually exclusive" - meta

Posted
I've combined movies with that before, but they always turn out lower quality or super large filesize.

If possible, use a better MPEG-4 based codec (H.264, WMV9 or XviD). Doom9 has plenty of guides on how to do this using fully open-source tools. Once you try x264 (or even XviD), you won't ever want to use any other codec again. Unfortunately, if you want to maintain compatibility with a standard DVD player, you'll *have* to use MPEG2, which really sucks. Yet, even if you have to use MPEG2, AviSynth has a bunch of filters that can be used to significantly boost your image quality and increase the compressibility of the video stream before sending it to the encoder.

Posted

Is it possible to use a better codec and then, afterwards, re-encode the spliced file for MPEG-2? Would that help?

OBSCVRVM PER OBSCVRIVS ET IGNOTVM PER IGNOTIVS

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OPVS ARTIFICEM PROBAT

Posted (edited)

Let's use AVC (high compressibility) and MPEG2 (low compressibility) as an example. I assume you are suggesting the following chain?

 

Raw video ---> AVC-encoded data ---> MPEG2-encoded data ---> Decoded video

 

We'll throw practical implementation issues out of the window for a while. Even conceptually, there's no way an MPEG2 encoding process can understand the data structures in an AVC-encoded data stream, or appreciate the algorithms that were used to construct the data. If it did, it MPEG2 would be able to provide compressibility as good as AVC! Therefore, the only way to convert an AVC-encoded data stream to an MPEG2 data stream would be to first re-construct the video stream via an AVC decoder, and then re-encode it using MPEG2, like so:

 

Raw video ---> AVC-encoded data ---> Decoded video ---> MPEG2-encoded data ---> Decoded video

 

The problem with this is that the moment you use a lossy compression algorithm such as AVC, you destroy some amount of data in your video stream, no matter how good the algorithm is. So it's always better to encode directly from the "rawest" possible source you have into your target format. Of course, as I mentioned, you can use a variety of filters to enhance and remove artifacts from your raw video stream before compression.

 

Raw video ---> (filters) ---> Filtered video ---> MPEG2-encoded data ---> Decoded video

 

I suppose (as you suggested in your question) you could look at an AVC encode-decode sequence as such a "filter". This is especially true since a lot of these filters perform some form of noise-removal, and co-incidentally, noise/grain-removal is a (sometimes undesirable) side-effect of AVC compression. In practice it is much better (and orders of magnitude faster) to use purpose-built filters for this.

Edited by angshuman

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