Movie compression

Okay, I now have a cut of the first three sessions at Lydden last saturday. I have a 4minute 320x240 movie running at 25fps with sound. I have rendered it out of Shake using the H.264 codec which gives nice results but an 80mb file.

What is the best way to get this down further - or is this acceptable? I can render uncompressed out of Shake and compress using divx, but my trial has expired, so i'll have to buy it.

Looking for something a little more free

Use virtualDub

either with XviD or DivX playing with the compression settings should allow you to compress to ~6 MB and still have a very good quality.

Oh - forgot to add - I'm on a Mac!

ok I'm out

Edit: have you tried ffmpegX ?

doom9.org will help you aswell

OK, this is a subject that I know something about.

You will not get better compression than H.264. It's what we use here at Sky for High Definition broadcasts. So if your file size is too large then what you need to do is reduce the bitrate until you get an acceptable trade-off between file size and quality. Bitrates for H.264 are typically half what you might use for MPEG-2. I encoded about 3 mins of higher resolution video using H.264 at perfectly watchable quality on my Mac and the resulting file was only 10Mb.

What bitrate (& other settings) are you using?

Originally Posted by lukemillar

Oh - forgot to add - I'm on a Mac!

And when you buy a proper computer, we'll tell you how to do it. Did I mention I dislike Macs?

DON'T use quicktime whatever you do, the codecs that come with it are simply rubbish (including their MPEG-4 codec). XviD should be available for the Mac, tis a pity you aren't using a PC, because I have always got the best file size/quality from windows media encoder (yes I know it is like shaking hands with the devil, but it really is good). If you want everyone to be able to play it, however, MPEG-1 is the way to go, yes it is ancient and the quality is not great, but it will play on anything. I'd be aiming for a file size of around 8 to 10 Mb for a 4 minute film.

MT

Originally Posted by wyrdness

OK, this is a subject that I know something about.

You will not get better compression than H.264. It's what we use here at Sky for High Definition broadcasts. So if your file size is too large then what you need to do is reduce the bitrate until you get an acceptable trade-off between file size and quality. Bitrates for H.264 are typically half what you might use for MPEG-2. I encoded about 3 mins of higher resolution video using H.264 at perfectly watchable quality on my Mac and the resulting file was only 10Mb.

What bitrate (& other settings) are you using?

I didn't limit the bit rate so it did whatever it fancied - coming up at 2500 kbits/sec which is rather high is it not?

What sort of bit rate should I be aiming for?

Empty - I have read you comments and am going to ignore them - this isn't a mac vs PC debate!

Originally Posted by lukemillar

I didn't limit the bit rate so it did whatever it fancied - coming up at 2500 kbits/sec which is rather high is it not?

What sort of bit rate should I be aiming for?

Some back of an envelope calculations...

For 'average' quality at 320x240, I'd suggest about 512kbit/s with H.264.
Your view of 'average' may vary. For web video you might get away with a lower bitrate, but for fast moving images you might need more. For 4 minutes of video, this would be a file size of approx. 15 megabytes.

I got away with 384kbit/s for some higher resolution video (512x288 I think), but there wasn't a large amount of movement. The picture quality was still great, even at this low bitrate.

H.264 was designed for low bitrate video such as web or videoconferencing, but then they discovered that it was great for high definition too, so it has become the standard for high definition broadcasting.