I am often given a DVD and expected to extract video and make usable files out of it.
I use nero recode which produces MP4 files.
After Effects can not read the files produced by Nero Recode. Quicktime can not play them either. Window Media Encoder always crashes halfway through. Media PLayer can play the file, but can not export the file.
On a whim I thought I’d give blender a try and was pleasantly supprised that blender can read MP4 files.
So I here is my problem:
I have a 688x544 MP4 source running at 29.97 fps. Forget the audio, I am just interested in the video portion of the file.
I run blender
Delete the cube
Create a plane
Move the camer over the plane so it is a top down view.
I add a mterial to the plane and apply the MP4 as a texture.
I delete the light in the scene and set the texture so illuminate itself. I also turn down the specularity.
Now I have a way to render my footage (yeah!).
BUT… There is some distortion in this method.
I am wondering how how high I should set my camera above the pane and what size the plane should be so I get a 1:1 ratio video transfer.
I hope you understand this and can offer some advice.
Try the Video Sequence Editor, it is available through the screen drop down list at the top. Import your movie, then set your output options and settings to get the frames out of the sequencer as a movie.
Check the wiki for VSE or Sequencer, and there should be a large amount of info from PapaSmurf on this - heck, just search his name here and you’ll see a wealth of information on this stuff.
yep, sequence editor is the way to go here (it will also be much faster)
Theres a preset window configuration for using the sequence editor. in the top header, use the pulldown menu and select the “sequence” option.
you should get a timeline and a preview window.
space->add->movie to open a file browser and select your movie. move it somewhere on the time-line. note the start and end frames, and set them in the render panel accordingly. hit “do sequence” in the render panel to activate the sequencer, then hit Anim.
for more info (theres a lot more stuff you can do than just conversion) check the wiki like craigomatic mentioned.
set the camera to orthographic, make sure it is above the plane, and play with the scale factor to fit the video plane into the viewfinder.
You need to resize your plane also to 43:34 to match the aspect ratio of that wierd size, or the image will be stretched. I dunno why you have that size, it’s a new one to me. If it was 720x480, normal TV, you would use a plane 4:3 scaled in the X:Y dimension (use the N key to set).
Using this technique you can crop out whatever you want by moving the camera.You can output in whatever format and size you want as well. You can also letterbox really easily by setting your world color to black and position the camera above the plane.
still, unless you get it pixel to pixel perfect and turn off OSA etc, your going to be losing information and/or getting aliasing due to re-sampling and reconstruction when you render with an image textured plane, as opposed to using VSE where as long as you don’t change resolutions, you will just be re-compressing.
It occured to me that I could just delete the plane and add a material to the world background color, assign the video, then all scaling issues would be moot.
I have already found a work around to using that poorly constructed MP4. That was my main problem, Nero 6 makes bad MP4 files. I have downloaded Handbrake (another open source).
well, I’m glad that you found a more direct solution to your encoding problem.
that said, if you do plan on doing re-encoding, or anything similar inside of blender, I would heavily recommend learning how to use the sequence editor. any solution using the normal renderer invokes a lot of overhead and will be much slower that just using the VSE. also, you run the danger of losing information, since to render, a discrete number of samples are taken then reconstructed using some filter. Depending on the setup, you will get information loss or aliasing.
of course, if you are just re-encoding video, not much beats virtualdub (another open source app) for speed.