Re: Video compression
- To: mathgroup at smc.vnet.net
- Subject: [mg108389] Re: Video compression
- From: Robert Pigeon <robert.pigeon at videotron.ca>
- Date: Tue, 16 Mar 2010 04:45:00 -0500 (EST)
Thanks for your answer Sjoerd, I agree with you: Import/AVI format lists what is available as formats. But... Do the following, it is an AVI format: Import["http://homepages.inf.ed.ac.uk/amos/demos/flythroughb.avi","VideoEnco ding"] Will give: CRAM Now do: Import["C:\\Users\\rpigeon\\Videos\\flythroughb.avi", "Animation"] Will give: Import::fmterr: Cannot import data as video format. >> So what I was asking is: the codecs used by Mathematica is a long way from all that is used for AVI encoding formats. The same is also true for other type of video extensions. Just try Importing a WMV video in Windows from the Video Samples directory and you will see that it cannot be used in Mathematica directly. Do I have to uncompress (UNCOMPRESS format is in the AVI list of format for avi and other type of videos) a video before using it in Mathematica? Or is there a way to do the uncompress inside Mathematica? Robert -----Message d'origine----- De : Sjoerd C. de Vries [mailto:sjoerd.c.devries at gmail.com] Envoy=E9 : 15 mars 2010 01:05 =C0 : mathgroup at smc.vnet.net Objet : [mg108357] Re: Video compression The vast majority of movie formats uses compression. So, if Mathematica can import a given video format is most likely that it is compressed. The help for the Import/AVI format says: "Import supports the following codecs: "YUV", "H261", "H263", "JPEG", "Uncompressed", "Cinepak", "MotionJPEG". " Looks like there are compressed video formats in there. Cheers -- Sjoerd On Mar 14, 12:13 pm, Robert Pigeon <robert.pig... at videotron.ca> wrote: > Hello all, > > As you all know we can Import a video in Mathematica 7 and > then explore frames for example. But, usually a video that is obtain from > the Net is in a compress form of some sort. Then frames cannot be extracted > to do some image processing. We cannot even play it in Mathematica. > > My question: is it possible to uncompressa video in > Mathematica or do I have to open the video outside Mathematica in a video > player and, if possible, save it in an uncompress form? > > Thanks for any help, > > Robert