[By Philip Hodgetts - This is one of the best explanations of the various codecs I've seen]
At 4:37 PM +0000 2/20/07, Carlin - BlueStar wrote: >See, that's the point. Almost everyone has Flash, and if not, its a >very quick download to get it. > >As I understand it, Flash video is basically MP4, right? As is Windows >Media 9... QT too, right? for web video? No, No and No. There is no similarity to MPEG-4 in Flash or Windows Media. Windows Media is it's own thing and it's SMPTE version is VC-1. It has no compatibility with MPEG-4. Confusion may have arisen by Microsoft incorrectly (and probably illegally) co-opting the *name* for their .asf codecs MPEG4v1, MPEG4v2 and MPEG4v3. These were not MPEG-4 video nor were they in the .mp4 container, which is *based* on the QuickTime container. MS were annoyed that the QT container was chosen for MPEG-4 so they tried to co-opt the name (Embrace and extend). They finally renamed MPEG4v3 Windows Media and subsequently released the rather good Windows Media 9 as wmv. QuickTime 6.2 and later supports MPEG-4 Part 2 in Simple Profile or ISMA compatible. QuickTime 7 gained support for MPEG-4 Part 10, aka Advanced Video Codec (and in the ITU space H.264). The codec can be used in .mov containers, which are not compatible with anything but QuickTime, or in .mp4 containers which are completely compatible with any player that supports MPEG-4 at the appropriate Part and profile (there are many profiles within Part 2 and within Part 10). Flash video is a bastard child in a vector-based format. Initially (Flash 1-6) it only supported still image sequences of limited length (39,000 frames comes to mine but don't quote me). Flash 7 introduced the Sorenson Spark codec, which is basically the H.263 video conferencing codec of a decade earlier. In other words, a bad, bad codec for quality compared with bandwidth. It wasn't not even competitive when it was introduced, let alone now. This is the Flash video codec that YouTube uses. Flash 8 introduced support for On2 corporation's VP6 codec, branded as Flash 8. it's an OK codec. In my testing it needed more bandwidth for the same quality than H.264 or Windows Media. > >Pretty sure Google Video, YouTube, and all the others are playing the >video as Flash video. Google video is using Flash 8/9 in a proprietary container. YouTube is using the (should be obsolete) Flash 7/Spark codec. The only one that has any relationship to MPEG-4 is MPEG-4 (.mp4). Although DivX *say* they are MPEG-4 compatible they are not really. Their video track is a great implementation of MPEG-4 Part 2 Advanced Simple Profile but it's paired with an MP3 audio track in an AVI wrapper. A true MPEG-4 file would be MPEG-4 video (Part 2 or 10) with AAC audio (Low or High complexity) in a .mp4 container. >My point for doing the Flash video is I hate having to load Real >player and Windows Media 9 or 10 and QuickTime on all my computers. >They always trash my prefs, and I don't like to do that to prospective >customers. Flash seems to be a lot cleaner in that respect. on the other hand I do like to watch quality video without it taking up my entire bandwidth, so there will continue to be a role for quality. >prospective client, web video still isn't all that impressive :) it can be if you avoid Flash and have encoding skills. -- Philip Hodgetts President, Intelligent Assistance "Big Brains for Rent" www.bigbrainsforrent.com Personal Blog http://philiphodgetts.com News, tips and the best resources for Apple's Professional Applications: http://www.proapps-hub.com Download now, it's free. --------------------------------------------------------------- WWWhatsup NYC http://pinstand.com - http://punkcast.com ---------------------------------------------------------------
