Anyone over here know video compression?

Posted by: zwei

Anyone over here know video compression? - 10/22/05 08:46 AM

OK ...I have quite a few home movies that I have saved on my HD as full-quality DV files. In short, I want to know what the best way to compress them to conserve space, but retain really high quality. First off, I'm not looking to use H.264. I have decided I want to use MPEG4-Improved for several reasons. <br><br>1. It encodes about a bazillion times faster than h.264. <br>2. I can import them into MP4 iMovie projects without having to wait for them to be converted again. (biggest reason) <br><br>If I use MPEG4-Improved, what are the best settings to keep the file as close to the original as possible, but still be worth compressing. I've looked all over the web for data rates, but can only seem to find them for h.264 ...which says a good data rate for 640x480 is between 1000-2000kbps ...what is a good rate for MPEG4-Improved? When I click around in the QT boxes a number of 6400kbps pops up in the bitrate field. I googled it and found that MPEG2 at 6400kbps is DVD quality ...what would be the equivalent of that in MPEG4?<br><br>Also, are there any lossless codecs in the list? If so, I may be interested in using that instead. <br><br>I also tried Apple Pixlet ...wasn't impressed with the results. <br><br>Thanks for any help!<br><br>
Posted by: Papa

Re: Anyone over here know video compression? - 10/22/05 10:38 AM

You can switch but you can't hide.<br><br>I am supposed to call a guy at 2pm to see if I can find the answer.<br><br>
Posted by: zwei

Re: Anyone over here know video compression? - 10/22/05 10:46 AM

haha ...I've been found out! <br><br>
Posted by: Papa

Re: Anyone over here know video compression? - 10/22/05 12:58 PM

The phone call didn't provide an answer. I didn't have much luck with a google search either. <br><br>
Posted by: Michael

Re: Anyone over here know video compression? - 10/22/05 01:29 PM

I've had good results with FFMpegX, but you can test the different options for quality and output size with any app. In QT just select and cut 1 min. of video. Open a new QT window and paste. Then export that to DV stream. You can then test any of your settings with that 1 min DV file.<br><br>
Posted by: zwei

Re: Anyone over here know video compression? - 10/22/05 02:16 PM

I've been looking around apple discussions too, apparently the MPEG4 support was screwed up a bit by QT 7.0.3 ...I have exported a couple of my DV files at 6400kbps with automatic keyframs. The quality looks great to me, but I get jerky playback (sometimes HORRIBLE) on my 733. Apparently QT 7.0.3 has had that affect on several users.<br><br>
Posted by: ezyrider

Re: Anyone over here know video compression? - 10/22/05 08:08 PM

MPEG 4 is the cheapest and best quality (QT Pro $30). Or just plain MPEG (I have the Apple MPEG2 component in OT Pro - $20). Otherwise I use Sorenson Pro (expensive at $299 but worth it, better quality than MPG4). <br><br>
Posted by: zwei

Re: Anyone over here know video compression? - 10/22/05 10:27 PM

So what data rate for MPEG4 would you suggest? At 640x480 keeping quality really high.<br><br>
Posted by: Topper

Re: Anyone over here know video compression? - 10/23/05 09:02 PM

I mostly work with DVPRO50 and Blackmagic DV codecs.<br>I also use Sorenson Video 3 and MPEG-4.<br>My preference for MPEG-4 is 2000 kbps. <br>It isn't anything that I read about. I took most of the QuickTime codecs and made tests with each of them. The 2000 kbps looked good while keeping a fairly small file (at least when compared to DV codecs).<br>I am not sure what you mean by "are there any lossless codecs in the list?"<br>Do you mean MPEG-4 lossless codecs? If so, I haven't heard of any.<br>As I am sure you know with any lossless codec you will pay the price in file size and I thought that was what you are trying to avoid.<br>Otherwise Apple, Blackmagic, and Aurora have excellent lossless DV codecs<br><br>
Posted by: zwei

Re: Anyone over here know video compression? - 10/24/05 10:00 AM

Thanks for the reply ...i have settled on the following settings.<br><br>MPEG4-Improved, 3500kbps, Keyframe every 30, 128AAC audio/best<br><br>For some reason when I tested at 3500kbps before it looked rather crappy ...but I found out it was because I set the keyframes to auto. I figured Auto was best, but apparently not! <br><br>
Posted by: Topper

Re: Anyone over here know video compression? - 10/24/05 11:07 AM

Just did a test with your settings. Like them better than my 2000kbps.<br>The encoding rate is reasonably fast and the file size reasonably small.<br><br><br><br>
Posted by: ezyrider

Re: Anyone over here know video compression? - 10/24/05 02:44 PM

Sorry I was out yesterday and most of today. I'll concur with Topper. Anything at 2000 or above should do you just fine. I wish Auto would actually work but after lots of trial and error I go through and set everything manually. The formula you have looks like the way to go.<br><br>
Posted by: Topper

Re: Anyone over here know video compression? - 10/29/05 08:37 PM

FYI...I've been experimenting with BitJazz's SheerVideo codec.<br>To me it's an amazing codec. <br>It's file size is fairly small when you consider that it is a lossless codec.<br>Now for the bad news... it costs 149 bucks. But I think I am going to purchase it.<br>But you can download a demo version of the codec. <br><br>Here is what OneRiverMedia says about SheerVideo...<br>"Now here's a really cool codec. Imagine a lossless 4:4:4[:4] codec with alpha channel support that not only crunches the file size by half, but also works in real-time! In fact, this codec can render faster than real-time in most scenarios. This codec is dead accurate. And just because SheerVideo is new, don't think that BitJazz is new to the lossless codec game... they've been doing this for years with their BitJazz and PhotoJazz codecs. As of the initial posting of this codec to the OneRiver Media Codec site, the SheerVideo codec is free to use (with an expiration date on the codec). For now, this codec does not support 16-bit encoding. However, I've encountered incredible, near lossless results in 16-bit mode with this codec. Again, in real-time and half the file size! BitJazz has been adding some serious features to the SheerVideo codec, so I suspect they'll be adding support for lossless 16-bit encoding at some point. I also suspect we'll see complete integration with this codec in existing hardware, like AJA Kona SD, Pinnacle Cinewave and others. This is only a guess but the possibilities seem hopeful. For those that work in film and would like to edit in real-time lossless 4:4:4[:4], this may be the link to making that happen! For now though, you can use this excellent codec for pre-rendering, archiving or mastering with small file sizes and in real-time. Read: this is the fastest codec I've ever encoded to! Including real-time uncompressed codecs!"<br><br><br>