Video Compression Techniques

In the BDML, we often use the Mac G4 for our video editing and compression needs. Once the editing is completed, the next most difficult task is to make the video an appropriate size. This is where the magic of codecs comes in. We have often found success with the MPEG-4, DIVX and Sorenson3 codecs, which all have their advantages and disadvantages.

Codecs (COmpression/DECompression packages)

MPEG4

Advantages	Excellent support under Quicktime Good file size Good image quality
Disadvantages	Fair Windows Media Player support May need to download/install Quicktime

DiVX

Advantages	Good file size Good image quality
Disadvantages	Need to download/install special codec

Sorenson3

Advantages	Excellent support under Windows Media Player Good file size
Disadvantages	Fair quality

Software packages

We have found that several programs are used fairly frequently in the process of producing videos in the BDML.

iMovie

This is the easiest (and possibly fastest) way to produce a video. The buttons are fairly straightforward, and it doesn't take much to learn how to do something new.

Final Cut Pro

This is the more in depth way to produce a video. It can pretty much do anything that you can think of visually.

• FCP defaults to creating files with NO extension

Compression examples (w/FCP)

Sequence	Compression settings, size
EntireMovie_ICRA06	FULL Quality DV/DVCPRO - NTSC 720x480 => 315MB Looks like crap
EntireMovie_ICRA06	MPG4, 720x480, 29.97fps, 44.1k stereo => 463.4MB Used in below examples
EntireMovie_ICRA06	MPG4, 420x280, 29.97fps, 44.1k stereo, 768kbps => 148.5MB Used in below examples

(Apple) Compressor v1.2

This can be used to compress various file types to different MPEG(1/2/4) and other (AIF, ACC) formats. Once you get the hang of it, there are easy controls to set the frame size, bit rate, and other important options.

• Finder will not link files w/o an extension to Compressor (ie. rename FCP stuff to '.MOV')
• Compressor defaults to using '.MP4' as the file extension (for MPEG-4 compression)
• Windows seems to want to play '.MP4' files in QT

Compression examples (w/Compressor)

Before	After
MPG4, 720x480, 29.97fps, 44.1k stereo => 463.4MB	MPEG4, 720x480, 768kbps => 19.1MB
MPG4, 720x480, 29.97fps, 44.1k stereo => 463.4MB	MPEG4, 720x480, 640kbps => 16.2MB
MPG4, 720x480, 29.97fps, 44.1k stereo => 463.4MB	MPEG4, 720x480, 608kbps => 15.5MB
MPG4, 420x280, 29.97fps, 44.1k stereo, 768kbps => 148.5MB	MPEG4, 420x280, 768kbps => 18.7MB
MPG4, 420x280, 29.97fps, 44.1k stereo, 768kbps => 148.5MB	MPEG4, 420x280, 640kbps => 16.1MB

FFMPEG

This programs was identified by JonathanKarpick as a nice means to produce high quality MPG movies from Matlab. It can also be used to convert some movies to a MPEG1 version that works well in Windows Media Player. See MatlabMovies and the FFMPEG homepage.

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Raw notes from attempt to compress SpinyBotII video to under 16MB. The noted settings are what were explicitly specified in the export compression options menu. The remaining settings were left unattended unless otherwise noted.

05/09/07
-------------
Using Final Cut Pro to export SpineyBotII video
=================================================
(stuff in parenthesis is according to QT movie info after export)

Reduce SpinyBot2 video to 16MB
-CREATED new sequence EntireMovie_ICRA06
-TRIED MP4, Med quality, 300x200 (32k stereo, 1.3Mbps) => 25.2MB
-TRIED MP4, Hi quality, 480x320, 500kb/s (32k stereo, 5Mbps) => 89.4MB
-TRIED MP4, Hi quality, 480x320, 250kb/s (32k stereo, 3Mbps)=> 56.5MB
-TRIED Divx, 480x320, 150kb/s (32k stereo, 1.3Mbps)=> 23.8MB
--May want to reduce some content

Trying to find export settings that gave 3:10 @ 50MB
-TRIED Divx, 720x480, 2240kb/s (48k stereo, 3.6Mbps) => 82.9MB
-TRIED Divx, 480x320, 2240kb/s (48k stereo, 4.0Mbps)=> 92.8MB (!?!?!?)
-TRIED Sor3, Hi quality, 720x480, 290.5kb/s (44k stereo, 3.6Mbps)=> 81.2MB
-TRIED Sor3, Sml quality, 720x480 (48k stereo, 2Mbps)=> 47.4MB (?some major pixelization)
--NOPE-May try to re-export from iMovie (?)
-TRIED Cine, Med quality, 300x200, 2048kb/s (32k mono, 1.2Mbps)=> 28.4MB

Trying Mac Compressor program
-Using SpinyBotII_v33_Sor3.mov
-TRIED MPEG-4 Improved NTSC for Fast Cable Streaming (48k AAC stereo, 288kbps)=> 6.6MB
-TRIED MPEG-1 (Muxed, 1.4Mbps) => 32.1MB

Did some video edits
-Using EntireMovieBrighter10 as base
-CREATED Various Sequences ICRA, Outtakes Seq2 ICRA
--Moved outtakes to front
--Deleted the prodding section
-Adjusted the audio
-TRIED Sor3, Hi quality, 420x280 (44k stereo, 3.9Mbps) => 88.7MB
-TRIED Divx, 420x280, 15fps, 32k mono (780kbps) => 35.5MB
--TRIED Compressor MPEG4, 320x240 (32k AAC mono, 230kbps) => 20.1MB

05/09/08
===========
-TRIED Divx, 420x280, 29.97fps, 32k mono (1.3Mbps) => 30.4MB
--TRIED Compressor MPEG4, 320x240, 1024kbps (880kbps) => 20.1MB
--TRIED Compressor MPEG4, 320x240, 768kbps (680kpbs) => 15.6MB
--TRIED Compressor MPEG4, 420x280, 768kbps (690kbps) => 15.8MB
--TRIED Compressor MPEG4, 420x280, 512kbps (495kbps) => 11.3MB
--TRIED Compressor MPEG4, 420x280, 736kbps (667kbps) => 15.2MB
-TRIED MPG4, 320x240, 29.97fps, 44.1k stereo (4.9Mbps) => 111MB
--Exact same settings as Compressor that gave 15.6MB
---Very close - DIFFS=sound
-TRIED Divx, 420x280, 29.97fps, 44.1k stereo, 768kbps (30Mbps) => 688.2MB(??)
--Ended up DV/DVCPRO - NTSC 720x480
--TRIED Compressor MPEG4, 420x280, 768kbps (693kbps) => 15.8MB
--TRIED Compressor MPEG4, 420x280, 732kbps (721kbps) => 16.5MB
-TRIED AGAIN MPG4, 420x280, 29.97fps, 44.1k stereo, 768kbps (5.8Mbps) => 132.8MB
NOTICED THAT MANY OF THESE EXPORTS DONT HAVE THE OUTTAKES
-Reorganized the FCP project (fixed the outtakes issue w/cut&paste)
--New bin for ICRA06 (moved new sequences into it)
-TRIED FULL Quality DV/DVCPRO - NTSC 720x480 => 315MB
--Looks like crap
-TRIED MPG4, 720x480, 29.97fps, 44.1k stereo (21Mbps) => 463.4MB
--TRIED Compressor MPEG4, 720x480, 768kbps (860kbps) => 19.1MB
--TRIED Compressor MPEG4, 720x480, 640kbps (727kbps) => 16.2MB
--TRIED Compressor MPEG4, 720x480, 608kbps (695kbps) => 15.5MB
-TRIED MPG4, 420x280, 29.97fps, 44.1k stereo, 768kbps (6.7Mbps) => 148.5MB
--TRIED Compressor MPEG4, 420x280, 768kbps (840kbps) => 18.7MB
--TRIED Compressor MPEG4, 420x280, 640kbps (721kbps) => 16.1MB
-TRIED MPG4, 420x280, 29.97fps, 44.1k stereo, 768kbps (6.6Mbps) => 145MB (w/o SU logo)
--TRIED Compressor MPEG4, 420x280, 608kbps (690kbps) => 15.4MB

05/09/09
============
Used FFMPEG to converted EntMov_ICRA06_NoSU_MPG4_420_280_768k-Treys_MPEG-4_608k.mp4 to MPG
-forced 608k bitrate => 15.1MB
-ffmpeg -b 608 -i EntMov_ICRA06_NoSU_MPG4_420_280_768k-Treys_MPEG-4_608k.mp4 SpinyTest2.mpg
--CONVERTED to MPG1, 608kbps => 15.1MB

Removed the credit info at front
-TRIED MPG4, 420x280, 29.97fps, 44.1k stereo, 768kbps => 652MB (???) (w/o SU logo & credits)
-RETRIED MPG4, 420x280, 29.97fps, 44.1k stereo, 768kbps (6.5Mbps) => 143MB (w/o SU logo & credits)
--TRIED Compressor MPEG4, 420x280, 608kbps (695kbps) => 15.1MB
--CONVERTED to MPG1, 608kbps => 14.7MB

-- AMcClung? - 08 Sep 2005