.avi compressors

Akujiki · Post by **Akujiki** » Wed Jan 12, 2005 10:29 pm

Sorry if this is the wrong board, but I assume this is the place to query about this.

I just started messing around with Adobe Premiere and finished up a six-minute video, with the grand file amounting to over a gig in space. Now, I'm assuming this is normal, because as I said, first time using Premiere, but it seems a little big.

Using VirtualDub (I was using DivX Digest's FAQ on how to convert from .rm to .avi), the final file size was about 76 megabytes. While not as large, for six minutes of music and footage, that still seems a bit big.

My question is this: Did I do something wrong? Or are there better .avi compressors out there that can maintain good quality of video and shrink the file size even more?

greenjinjo · Post by **greenjinjo** » Wed Jan 12, 2005 10:32 pm

76 MB for a 6 minute video is actually small to medium size.

I don't quite follow what you are saying when you compressed your video, I think what I'm missing is why the video was ever in RM format.

As for avi formats, the most common is the DivX/XviD codec from what I've seen.

Akujiki · Post by **Akujiki** » Wed Jan 12, 2005 10:41 pm

The clips I was using for the video were originally in .rm format (I guess whoever uploaded them used Realplayer or something). I'd successfully managed to convert two of them to .wmvs using Windows Movie Maker, but it stopped working, so I had to find an alternative. Got a .rm to .avi converter and used that a bunch.

What I mean by compressed is that apparently, when Premiere makes an AVI, it is a pure, uncompressed form, because the file was roughly 1.24 gigabytes. In order to make it consume less space than the program required to make it, I had to compress it. So I used VirtualDub and the DivX 5.2.0 codec and it shrunk it down to about 75 megabytes.

I just had no idea that most of these were that big. I could have sworn the biggest I had was around 30 megs.

greenjinjo · Post by **greenjinjo** » Wed Jan 12, 2005 10:48 pm

Akujiki wrote:The clips I was using for the video were originally in .rm format (I guess whoever uploaded them used Realplayer or something). I'd successfully managed to convert two of them to .wmvs using Windows Movie Maker, but it stopped working, so I had to find an alternative. Got a .rm to .avi converter and used that a bunch.

I'm going to pretend I didn't read any of that

Akujiki wrote:What I mean by compressed is that apparently, when Premiere makes an AVI, it is a pure, uncompressed form, because the file was roughly 1.24 gigabytes. In order to make it consume less space than the program required to make it, I had to compress it. So I used VirtualDub and the DivX 5.2.0 codec and it shrunk it down to about 75 megabytes.

Actually, this is not true. Premiere is not spitting out a pure, uncompressed AVI, especially not if it's only 1.24 GB. Do you know which codec Premiere is using to compress its export Avi? A common one is HuffYUV.

I suggest that if you are going to compress in a DivX format to use the XviD Format as described by this helpful guide.

Akujiki wrote:I just had no idea that most of these were that big. I could have sworn the biggest I had was around 30 megs.

It really just depends on how high you want the quality. You could have them that lower or even lower, but quality will obviously suffer as you reduce the file size.

Hope this has been of some help.

Akujiki · Post by **Akujiki** » Fri Jan 14, 2005 12:12 pm

Considering it's not footage of:

1) Licensed anime

2) Not even an anime at all

3) It's video game clips, which as far as I know, is not illegal at all, because you're not playing the game

I see no violation of the first link. Considering I have no way to transfer the footage from my PS2 to my computer for use, getting it from someone else who can.

Thanks for the second link as well.

Esc · Post by **Esc** » Fri Jan 14, 2005 3:27 pm

1. Premiere exports the video (and audio) in format that you will tell it to. 1 GB is definitely too small for 6 minutes. So it was not uncompressed. Which codec was it, I do not know.
2. 75 Mb for 6 minutes is too much for my taste. If you have the same taste then let's think what could affect that.
2.1. Too much bitrate.
2.2. Audio is still not compressed (more likely).

Qyot27 · Post by **Qyot27** » Fri Jan 14, 2005 4:18 pm

Premiere is usually set for DV-AVI export. The only deciding factor (if it wasn't DV, or maybe even if it was) that would affect the filesize would be the resolution and frame rate. It's perfectly possible for a 6-minute video to fit into 1 GB, but it's probably not going to be DVD res.

Anyway, the basic standard datarate for DivX or XviD is considered to be around 1 minute of video per 10 MB, so considering it popped out at 76 MB for six minutes worth, it means your video bitrate is higher than the accepted standard, or (and this is most likely the case) the audio isn't as compressed as it could be. Premiere's default audio export is IMA ADPCM, I believe, and 32kHz at that (*shudders*). You probably didn't specially process the audio in VDub for the final export (or did you?) and left DivX set on it's defaults or at a higher bitrate that you yourself set. Considering that scenario, it doesn't surprise me it turned out that large. A six-minute video compressed to 30 MB will usually look like complete crap unless you know what you're doing (and even then it probably won't look perfect).

To fully realize the potential of filesize vs. quality, AVISynth can filter your video and that helps tremendously when you send it to XviD to encode. Normally, if there isn't interlacing in your video, you'll want to use at least a smoother (like Deen) and a resizer (I tend to use Bilinear for my Org releases, but you're free to use Bicubic or Lanczos if you want). Then you'll want to follow the guides on how to encode to XviD to take advantage of that.

Of course, the popularity of MPEG-4 AVC will grow a lot since it's becoming easier and more widely available now. This is a highly experimental codec (at least in the public realm). In the tests that I ran with x264 (both binary and ffdshow versions), it's not quite as intuitive in determining output bitrate as XviD is, so the bitrate will probably stick pretty close to the bitrate you set for it, but you can easily drop that bitrate further than you could with XviD. It just takes a little experimentation on your part to find out where it is safe to drop it to. I still haven't worked with it enough to know where I'm comfortable, but using AVC will definitely improve that quality front while maintaining a low filesize. It's just not very common right now, and you'll have to make sure to install a decoder for it (whether it's ffdshow or some other). There's a thread in the General Video section that has links to various software needed for this kind of encoding, as well as a basic guide to how to encode with it using ffdshow.