avi is too large to fit on the cd!

[Acid]

hello everyone,

i've got a prob i have a movie which doesn't fit onto a 700MB cd. does
anyone know how to compress a divx avi? it is only a couple of mb larger
then cd...
i have learned that it is possible to compress the movie without a quality
loss using a combination of fast and low motion codecs. So that's what i
did, I created 2 avis one with 500 and the ther 2000 kb/s
then i used projectdivX 1.6 to combine it but when play the final avi it
plays very fast and you can't make anything out of the sound... both low and
fast motion compressed avis play ok when separate...
does anyone know what the problem is? maybe i should use other soft?
i tried most of the other progs from www.divx-digest.com but they either
didn't work or they showed errors...
if anyone has other solution to this porblem pls let me know

Pasha

[Enchanter]

A much less complicated and yet better way would be to simply crop off the end credits of the movie. Here's how:

1. Open File in Virtual/nandub
2. Set both Video and Audio tabs to Direct Stream Copy
3. Use the Mark In/Out buttons on the main interface to set the beginning and ending of the new movie respectively. In this case, the start of the original movie will be the beginning and the part just before the end credits appear (or whereever after, as you think suitable) will be the ending
4. Go to File -> Save as AVI... and give a name to the new file

Another way would be to recompress the audio at a slightly lower quality so that the final AVI size falls to 700 MB or just below. However, this is a loss of quality (reencoding a lossy format with a lossy format again is NEVER a good idea), and I would not resort to this unless the above method does not apply (ie. the end credits have already been removed).

[Acid]

thanx for the reply but this is one of the three cds of the movie and i can't cut anything here
i am also not very enthusiastic as for recomressing it with a lower bitrate due to quality loss, that is why i thought someone could help me use the compression method i mentioned before

[Acid]

oh by the way its an ac3, any ideas how to recompress it? it's 448 i thought i could use somewhat lower bitrate

[Enchanter]

That makes things a little more complicated than I originally thought.

I'm not sure if you can compress an AC3 sound stream, but I doubt you can. In that case, I would decode the audio to WAV and compress it to MP3 (a high-bitrate one, of course). BeSweet will do the job of decompressing to WAV for you and LAME can do the MP3 encoding. As for the bitrate of the MP3, it should be safe to use a value as high as 320kbps, given that the bitrate of the AC3 stream itself is 448.

[Acid]

ok thanx for hel i'll try that

[khp]

Originally posted by Enchanter

I'm not sure if you can compress an AC3 sound stream,

One could probably use AC3Machine to recompress it.

http://www.doom9.org/software2.htm#audio



i have learned that it is possible to compress the movie without a quality
loss using a combination of fast and low motion codecs. So that's what i
did, I created 2 avis one with 500 and the ther 2000 kb/s
then i used projectdivX 1.6 to combine it


This is will most cirtainly result in some loss of quality. And you would most probably get better quality by doing a two pass encode with divx3.11(nandub) or divx5.

The method you descripe is just a very primitive version (stoneage) of what nandub does.

[Enchanter]

One could probably use AC3Machine to recompress it.
And can I readily play that compressed AC3 file right off the AVI without having to perform some sort of 'decompression'?

[khp]

Originally posted by Enchanter
And can I readily play that compressed AC3 file right off the AVI without having to perform some sort of 'decompression'?

No, you would probably have to extract the ac3 file first, recompress it, and mux it back into the avi file. But I have to admit, that I have never done any of this.

[Enchanter]

Uhh...you misunderstood me. I meant this: I compress AC3 file. I mux the compressed AC3 file onto the AVI. Will I be able to play the AVI file with the compressed AC3 file right away without having to install anything fancy (ie. will the appropriate video codec along with the AC3 codec do for this situation?)

[Enchanter]

Follow-up:

I'm giving the program a try and it is interesting to see that it recompresses the AC3 file to another AC3 file with a different bitrate.

Currently, I'm compressing a 384Kbps AC3 to a 256Kbps one. I'm just wondering what information is lost with this compression and if it will be audible at all. I'll try a few listening tests later (maybe much later though) and see how it compares to the MP3 I've already created from the same AC3 file. Frankly, the word AC3 compression I originally had in mind was a lossless type, but I think I'm asking too much there. ;)

[Acid]

khp, could you describe in more detail how to do this two pass encode with divx5?

or point me to some source where i can read more on it?

[Acid]

hi guys, i recompressed the ac3 at 320kb/s and merged it back to the video with nandub. the filesize is just what i needed but the problem is that when i play the final avi the sound is very low compared to the original, how can i normailize it or something?? when i am trying to use volume option in nandub it gives me some error...

[khp]

Originally posted by Enchanter
Uhh...you misunderstood me. I meant this: I compress AC3 file. I mux the compressed AC3 file onto the AVI. Will I be able to play the AVI file with the compressed AC3 file right away without having to install anything fancy (ie. will the appropriate video codec along with the AC3 codec do for this situation?)

Ahh sorry about that. I would expect it to work with the AC3 decoder filter, but I have to admit that I have not tried any of this.

[khp]

Originally posted by Acid
khp, could you describe in more detail how to do this two pass encode with divx5?

or point me to some source where i can read more on it?

Part 1 of this page explains the basics of avi recompression in virtualdub with divx5.

http://www.divx.com/support/guides/guide.php?gid=4#part1

But because your file has AC3 audio you will probably have to encode with audio disabled, and then mux the audio in to the avi file afterwards.

[khp]

Originally posted by Acid
hi guys, i recompressed the ac3 at 320kb/s and merged it back to the video with nandub. the filesize is just what i needed but the problem is that when i play the final avi the sound is very low compared to the original, how can i normailize it or something?? when i am trying to use volume option in nandub it gives me some error...

Sorry, as I told enchanter I really don't have any experience with encoding AC3 files. I guess should learn not to give out advice like that, sorry.