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.avi File Compression


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It depends on what you want to do with these files later on.

Zip or RAR compressors are not going to help you, you need "codecs" to compress video files.

Download something like VirtualDub and K-light codec pack. K-light will install codecs and VirtualDub will compress your files. Xvid and DivX are probably the best codecs around these days, and .avi encoded with these can played on some DVD players.

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Agree ^^^

Do be aware that all of the CODECs use 'lossy' compression, unlike zip, rar etc they throw away data making impossible to recover the original quality. The loss of data may or may not be noticeable.

Using these CODECs also makes the files more difficult to edit. Do your editing with the original uncompressed files the compress the final version to your required medium. Probably best to compress to DVD (mpeg2) for archiving.

Personally, my camcorder supports save to tape so I can edit and then save back to tape with NO loss of quality :o

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Unless your DVD player supports DivX or Xvid (they are very similar, one is open source another is licensed but free), you should convert your files to DVD standard - mpeg-2, not avi.

For that you'll need a DVD authoring program, and they cost money. In Thailand you can, of course get all sorts of illegal software. Maybe if you buy a DVD writer it will come with Nero OEM, that would be legal.

Once you have the software it's relatively easy to create a new project, drop your video files in it, slap together some menu with chapters, and the program will do all the conversions for you.

But just for comparison - a regular, 4.5 GB DVD disk can hold about six movies in DivX, or one movie in DVD format.

DivX is also very flexible about the size, if you want better quality just set a higher bitrate and set compression in two passes, not one.

Edited by Plus
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An AVI extension is just a generic video extension. It can be encoded with one of many thousands of codecs. The one that comes from DV cameras is of course the DV codec, and depending on what capture program you used, it may be Type 1 or Type 2 (they're not the same, and certain programs won't accept one or the other). 1 hour of DV video usually takes 12 GB, but it's of the original (best) quality, so as stated above, when editing you edit with the original codec. Only when you finish editing do you encode into a smaller but poorer-quality codec, like DivX or Mpeg2.

VirtualDub is a nice and flexible (and most importantly FREE) program to encode AVIs. Problem is that it's not very user-friendly. TMPGENC is a good program for encoding mpeg streams (which the original VD doesn't do).

Most modern DVD players will be able to play DivX or Xvid files, but pretty much all DVD players can play a Mpeg-2 encoded and authored DVD.

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I understand that DVD codec, mpeg-2, is licensed and so no program can provide conversion to mpeg2 for free, they have to pay royalties themselves.

Avi to mpeg converters are never free, as far as I know. Tmpgenc free version cannot convert to mpeg2, for example.

Actually you can have a look at this website, I can't keep up with their content updates:

http://www.videohelp.com/tools/sections/al...-dvd-converters

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if you just want to reduce size then DivX or XviD is best, you can play these file either direct video link to your TV from PC or write them to CD and play them on a compatible DVD player, quite a few DVD players (about 80%) have the DivX logo. There are also recording devices that will record in this format too which is very handy, phones, video cameras etc. This means you can take these small hi quality files and write them straight onto a CD to watch in your DVD player, soon to come to market will be DVD wifi/network enabled devices and setop boxes that will all play DivX files straight from your PC via wifi or lan, hopefully we will all have DivX compliant phones, PDA's, video cameras, DVD players etc. then we will have a video standard that works for all, I am currently watching a DivX movie on my TV right now and the quality is superb, file size in DivX AVI format is 700mb origonal DVD almost 5gig.

Currently getting a video from your phone or video cam or other recording device to where you want to store and watch it is a nightmare because you have to convert different formats for different devices.....DivX could change all that soon.

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There have been quite a few network-enabled media boxes on the market for several years now, and most can play Divx. However, it's doubtful that divx will actually be the codec of the future. Codecs are constantly changing, as well as content, so any single codec, even if it evolves, cannot keep up with the changes. In the beginning, it was uncompressed, then a bit compressed (indeo and such), then a bit more compressed (mpeg, mpeg2), then a bit more compressed (divx, xvid), then even more compressed (AVCHD, etc). There are different codecs for different applications.

However, one thing remains clear: you cannot get the same thing for less. With each iteration of compression, you lose more and more information. It might not be obvious to the naked eye in many situations, but picture information is getting lost. Try watching the typical 600MB divx ripped from a DVD and comparing it to the original 8GB mpeg2 stream. You'll definitely see differences, usually in the form of blockiness, jaggies, poor motion, or lost color information.

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If you're editing, use the original HUGE files.

If you want to burn to DVD, generally use the software that came with your DVD writer (I have Nero),

Or, if you're in luck, and your DVD player plays Divx (or XVID), you can use VirtualDub to generate .avi files encoded using those fairly easily. (a little google should cover it).

If you're only wanting to keep the files for watching on your PC, I personally prefer H.264 (aka. AVC) as the compressed files are generally better quality at the same bit rate than Divx or Xvid. But it takes a lot more cpu to do the H.264 compression.

Divx / Xvid (simple mpeg 4), and H.264 / AVC (complex mpeg 4) are all suitable for playback on Ipod, Apple TV, Sony PSP. - although you may have to adjust the resolutions for specific devices. (they need to be mp4 files rather than avi - but that's just the container).

As for the discussion on changing codecs. - H.264, WMV (microsoft) and mpeg 2 are the ones that are allowed for HD movies on Blu-Ray and HD-DVD, so that probably constrains the likely output formats from your PC for the time being. If you're keeping it on the PC, fractal compression has some nice characteristics (mainly to do with not looking jaggy when you scale it up), but it's too CPU intensive (until we all have 8-core processors probably).

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I think DivX has passed its peak. The main reason behind its popularity, to fit an illegaly downloaded movie to a CD, has lost its urgency. CD burners are becoming extinct and replaced by DVD writers and prices of blank DVDs are comparable to blank CDs.

Also download speeds have increased. Theoretically speaking you can have a live feed of a DivX movie even on Thailand's connections.

Surely torrents are as popular as ever, but it's mostly the lower end of the world catching up. On usenet there are more fill DVDs and High Definition movies than movies in DivX. People don't mind spending a bit more time on downloads to get better/perfect quality.

Initially I used to leave computer on for the night to download something. Now I can get two-three movies done when I wake up - I don't have time to watch them. I wish there were more HD torrents as Usenet is not free.

To the OP - if you worry more about quality than space, convert your movies to DVD. If you find that DivX qiality trade off is minimal, convert them to DivX. It's easier and it's free.

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Shooting film on the camcorder, transfer it to the PC. Files are ###### huge to say the least. Need some kind of compression s/w that reduces the size to something more manageable. Suggestions please.

Avi2Dvd might be able to do that.

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