video encoding

Okay, over in the "Climber's Talk" forum, "Chunking down", Roger Barnett posted a video he'd captured Tue Jul 16 15:13:40 2002 (local time, likely) with a digicam held vertically. I took a stab at rotating it, but was informed by Leon that it was encoded using a codec he did not have on his system, thus he was unable to play it. I'd not specified any particular codec when re-encoding it, so evidently the software defaulted to the "open" version of DivX. On a second version, I'd specified the same(?) mjpeg codec as was used in Roger's attachment.

How's about letting me know how the various attachments "play" for you all?

I guess it goes without saying that oftentimes folks who do stuff with computers, even professionally, make assumptions about other's working environments which ultimately prove to be untrue.

Taking the example of a web page or "office" document, it's okay to doll things up in certain ways, of course, but one should never assume that others who will view the result will see it exactly as you did. The only (or main, anyway) way to ensure the "experience" remains the same is to use something like PDF. Different web browsers render things slightly differently, and users may or may not have access to particular fonts, they may have a different size screen and/or don't expand the browser window to be full-screen, etc. Also, "word" documents were never designed to render exactly the same (as are PDF) everywhere; "word" is only designed to specifically print a document locally, not, as is often assumed, to render it the same on any other computer at any point in time.

Back to the subject, I used a program called "mencoder", part of the "mplayer" package. For my first effort I'd used the command:<font class="small">Code:</font><hr /><pre>mencoder -oac copy -ovc lavc -vf rotate=2,eq2=1.6 37737-MVI_0159.AVI -o rogers.avi</pre><hr />
and for the second I added the option:<font class="small">Code:</font><hr /><pre> -lavcopts vcodec=mjpeg</pre><hr />

Have a look at the attached zip file which contains two HTML-ized versions of the unix "man page" for mplayer/mencoder. One is done via the KDE system I use parts of, and the other is done via the "standard" "man page" tools. When you see this, you'll understand why the MS "help" stuff is considered to be so weak and lame by some of us :)
 

Attachments

They both gave me good audio but a white screen...no picture at all.

I looked at the attachment...way beyond me. I did some Xenix years back, very similar but I have been spoiled by WXP.
 
It seems as though the Windows media player doesn't know anything about the standard ISO-MPEG-4 data stream. I had to modify the encoding to use the "vcodec=msmpeg4v2" qualifier before I could get it to play on a (yuk!) Windows partition. Further example of their "embrace and extend" mentality/practices which they habitually use to squeeze out "competition", I guess. Too bad they're not a little more concerned with their customers' best interests.

By the way, you folks really should be very careful these days. The latest known exploit is not against your IE or Outlook, but against the very core of Windows "functionality". Your best bet evidently is to unregister the WMF handler (which will disable thumbnail image generation for your filesystem "explorer", among other things, though doing so will still not protect you completely), run either Opera or the latest Firefox browser, and don't open any HTML-formatted emails until MS gets their ass in gear with a fix (if they can).
http://www.eweek.com/article2/0,1895,1906513,00.asp
http://www.kb.cert.org/vuls/id/181038

Anyway, here's the "properly" encoded video. It's a shame that it's so difficult for me to find out whether these work in Windows or not because everything I've seen so far is handled immaculately by "mplayer" and "xine" (the only two players I've tried under Linux).

The command to produce this attachment from Roger's original was (all one line):

mencoder -oac copy -ovc lavc -lavcopts vcodec=msmpeg4v2 -vf rotate=2,eq2=1.6 -of avi -o rogers4.avi 37737-MVI_0159.AVI

There are further options for tagging the file with information regarding "name", "artist", "genre", "subject", "copyright", "srcform" [original format], and "comment". As copiously covered in the "man" page. As well, much could evidently be done to clean it up "videoly" in general.

Ekka, my point by introducing the man page was regarding the capability of the software and the complete, detailed documentation included with it.

I understand there are also graphical front-ends for it, but such things are almost always slower and more complicated to use, not to mention not being "automateable".

By the way, Ekka, "aluminium" might be pronounced "al-you-min-e-um", but "aluminum" (the metal) is pronounced "al-u-min-um", hahaha!
 

Attachments

Ha ha Glens, where did you read that?

Oh, the vid works fine now, but I still dont know what all that codec and stuff is ... I just "plug and play".

All beyond me, but well done anyway. Cheers
 
It was in one of the threads at Butch's that you provided links for here yesterday.

Say Roger had a whole directory full of these videos that were filmed with the camera on its side. He could get into the directory within a command prompt window, then type in a command something like<font class="small">Code:</font><hr /><pre>for %i in (*.avi) do mencoder -blah -blah %i -o %i-rotated.avi</pre><hr />(I omitted the particulars to keep the line length reasonable, and the Windows way of forming such a command may not be exactly represented) and he'll have fresh new rotated copies right alongside the unmolested originals. Granted, it might not be as "easy" to have to type in and execute the command as it might be to click a couple of check boxes in a window, but how much time will it take to do the manual command once as compared to going through the whole graphical process for each file?
 
Well, sounds like a good idea if he can manage it.

Golden rule when videoing is DONT turn the camera on its side ... I learnt that early in the piece.

Plus if you do turn the vid 90degrees you end up with a pretty thin video with bands on the side.

That's the whole idea of wide screen, it's more natural to human vision. We see more horizontally than vertically when we look at something. Cinema is wider again. But you'd think that when they went to wide screen that it would have been the same but that would leave cinema with no advantage and manufacturers nothing to phase up to.
 
True, but nobody who's taking "video" clips with a digicam is producing anything that looks good full-screen anyway (unless you're talking full-screen on the 3" camera display). Compressed bitmap images don't scale up well at all, at least not scaled up very much.

Hey, check out http://www.virtualdub.org/ and let me know how it stacks up with what you're using now. I can't remember if it was the package or not, but one of the ones I was looking at mentioned being able to "batch" process files.
 

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