MJPEG Problem: Has anyone else come across this problem?

[Corran]

The other day I decided that I wanted to make a bumper that I can use on all of my future videos using footage from the opening/ending sequences to six different animes.

Two of the animes use a 1.78:1 ratio where as the rest use 4:3
Sooo... If figured instead of editing them in their native DVD resolutions of 720 by 480 and ending up with a bumper where a third of the video would be out of proportion with the rest, I decided to convert them to a resolution that fit their respective aspect ratios.


First I ripped the vobs and created avisynth scripts for them. In the Avisynth scripts I cropped the scan lines out and resized them to the following resolutions.

Love Hina, Cowboy Bebop, Orphen, and Rahxephon: 640x480

.Hack//Sign and Noir: 640x360

Next I used virtualdubmod and the PICVideo MJpeg Codec to create the avi files that I would edit with in Premiere.

Because 640x480 is my larger resolution of the two I set up my project settings off of that. The rest such as Timecode 24fps picvideo for preview files so on and so forth I set up just like any other video I would work on.


For my 2 video clips in 640x360 I told Premiere to maintain the aspect ratio by right clicking on them and selecting the respective option in 'video options'

Next a placed a 640x480 clip in 'video 1' and a 640x360 clip in 'video 2'; clicked on transparency for the 640x360 clip and selected alpha matte so instead of premiere showing black bars to make the clip 640x480 it would show the clip underneath instead.


By holding down the alt key and scrubbing the timeline I verified that the alpha matte works and that the 640x360 clip is correctly superimposed on the 640x480 clip.

So far everything is working just fine. Then I render a preview...

The video I end up with is pretty messed up. Tomorrow I should be getting internet in my room(was supposed to get it today ) so I can upload a screen shot (I'm at the library right now) but for now I will try to desribe what I see to the best of my ability...

Ok. The only thing really messed up is the 640x360 clip, the 640x480 clip underneath still looks fine. Within the 640x360 clip it looks like the video was cropped by 60 pixels on the bottom, shoved down that amount and a 60 pixel thick black bar was attached to the top... wtf?!?

neways I tried messing with all of the various Video options that Premiere uses and transparency settings and had no luck. After about 30 minutes I replaced the 640x360 MJPEG clip with its avisynth version and it worked fine.

Great! I narrowed it down to the MJpeg codec... however... that meant I couldn't use that codec to edit with (at least for the two 640x360 clips). Now... the bumper is only going to be about 15 seconds long anyways so editing with 2 avisynth files probally won't be so bad, nonetheless I am troubled slightly by this problem and am curious if anyone has found an answer. Just in case I actually end up editing a multiple source, multiple aspect ratio video in the future so I know how to handle this.

[Corran]

BTW the library closes in like 7 minutes so I won't be able to see any responces untill tomorrow...

[the Black Monarch]

Assuming that you're using MJPEG for the bait-and-switch method rather than as a HuffYUV substitute, my only recommendation is that you use Indeo or some such nonsense.

[Tab.]

I doesn't sound like the mjpeg renderer could cause something like that to happen...
anyway, don't listen to Black Monarch as usual, and probably just try using the avisynth files for now.

[Corran]

Looks like it will be one more day till I can get the screenshots up...

Oh well. Yeah, editing with the AviSynth files won't be too bad so I will just stick to that for now.

If anyone finds anymore information however please let me know.


Thank you.

[SS5_Majin_Bebi]

I sometimes get that error editing cropped 4:3 (formerly letterboxed) video in full frame mode; i do the whole right click > maintain aspect ratio, and every now and again it does exactly what you've explained, either that or it winds up lookng like someone slashed a razorblade across the picture and performed a very bad splice on it. The thing is, the problem is totally inconsistent, affecting one lot of settings one day, a whole different set the next day, and vanishing the next day after that, only to reappear again when I least expect it. Regardless of what codec I use. I'm thinking it has something to do with Premiere incorrectly rendering the footage due to the aspect ratio difference, but given my rather paltry knowledge of all things video, I could be well wrong.