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Motion JPEG A or B? what is the difference??
Posted: Fri Jun 23, 2006 5:42 am
by komunikator
after trying out different kinds of compression formats the best results i got in the end were from Apple Motion JPEG A and
Apple Motion JPEG B. i kept in mind all the usual compromises: size, quality, performance.
what i dont know about is the difference between these two codecs, if there is one. as far as i can tell they look the same in comparison and size seems to be about equal.
does anyone here has any experience with these compression
formats and any info about the difference between A and B?
Posted: Fri Jun 23, 2006 9:06 am
by yves@garagecube
Here is a description:
Motion-JPEG (M-JPEG) is a variant of the ISO JPEG specification for use with digital video streams. Instead of compressing an entire image into a single bitstream, Motion-JPEG compresses each video field separately, returning the resulting JPEG bitstreams consecutively in a single frame.
There are two flavors of Motion-JPEG currently in use. These two formats differ based on their use of markers. Motion-JPEG format A supports markers; Motion-JPEG format B does not. The following paragraphs describe how QuickTime stores Motion-JPEG sample data. Figure 3-1 shows an example of Motion-JPEG A dual-field sample data. Figure 3-2 shows an example of Motion- JPEG B dual-field sample data.
Each field of Motion-JPEG format A fully complies with the ISO JPEG specification, and therefore supports application markers. QuickTime uses the APP1 marker to store control information, as follows (all of the fields are 32-bit integers):
Quoted from:
http://www.devworld.apple.com/documentation/QuickTime/QTFF/QTFFChap3/chapter_4_section_2.html
Posted: Fri Jun 23, 2006 5:24 pm
by komunikator
thanks for the info.....do you guys [garagecube] use this kind
of compression? and if so to what results?
i'm in the process of cutting up some old footage, black and white, taken from dvds. i'm using MPEG Streamclip to retrieve
the videos, cut, and compress. i've tried animation, video, sorenson, cinepak, and whatever else Apple has and the best results were from Motion JPEG. when using MPEG 4 compression,
after loading the same clip on 4-5 layers it'll start being sluggish which is pretty much what happened with a lot of those
other codecs. do you guys have any other suggestions for best results when using compressed video in modul8?
i did look at the 'how to prepare your media' post in FAQ section and i am scaling down to 512x384.
thanks in advance_
Posted: Sat Jun 24, 2006 3:09 pm
by sigmasix
In the FAQ they suggest Photo-JPEG, it's what I use and it's good solution
Posted: Sun Jul 02, 2006 6:58 pm
by komunikator
yes, photo-jpeg seems to be better at compressing.
thanks for the info_
Re: Motion JPEG A or B? what is the difference??
Posted: Tue Feb 23, 2016 9:43 am
by zamara
after loading the same clip on 4-5 layers it'll start being sluggish which is pretty much what happened with a lot of those