Video Sequence Editor previews & renders video incorrectly (mixed up pixels) on OSX.

Hey Guys,

I just bought a new MacBook Pro and I’m having trouble editing video on it (which I have been doing in blender for years) because it messes up the source material.

This is a close up of the problem:
(click on the picture to see a larger version on twitpic)

I have never seen this before. It is not interlacing, because interlacing causes a jagged edge to appear, not mixed up pixels like shown here. Checking the deinterlacing function in blender therefor doesn’t solve the problem.

I have tried several types of files (.dv, .avi, .mp4) from several sources (DV camera, point and shoot camera) with and without interlacing. All material shows this problem. An interesting fact is that the video looks great as long as I watch it at 50%, which means the mix-up happens within 2x2 pixel blocks.

I’m on a 2.4GHz, 4gig MacBook Pro running OSX 10.6.4. Since I bought it last week and software update says I don’t have any updates, I’m assuming my video drivers are up to date.

Any help would be GREATLY appreciated! I bought this computer with smooth video editing as one of the primal usages in mind, and I’d hate to have to start using one of the Big Packages.

You don’t mention whether this is 2.4xx or 2.5. But suggest updating your FFMPEG to latest. svn version preferably. It’s a FFMPEG problem. Also if you’re on 2.5 FFMPEG is no longer bundled with blender but uses your system version instead.

As an aside, unless things have changed, even svn FFMPEG / Blender is going to scale the luma in your video sources in the YUV to RGB conversion when you import unless your video is progressive rather than interlaced.

Hey Yellow,

Thanks for your quick reply! I wasn’t aware of the availability of the 2.5 build. I have installed 2.5 alpha 2 and video is looking alright now. I’m not sure if there are many differences between 2.5 and 2.49b but I guess I’ll just keep using this version.

Thanks a lot!

Eckie, you may struggle with 2.5’s sequence editor, not everything has been transferred, don’t think proxies work??, new stuff has been and continues to be added though. :slight_smile:

I personally still use 2.49b for vid editing, built from source as it is now. There are a few updates in that branch occasionally and it seems to compile using system FFMPEG rather than it’s own supplied one meaning latest FFMPEG from svn.

Good luck. :slight_smile:

I’m not really into the open source scene that much that I know how to compile blender or FFMPEG from svn, which is why I thought 2.5 would be the way to go for now. (Although obviously I know my way around blender < 2.5 way better.)

I went to the FFMPEG website but didn’t really understand how to update my FFMPEG install. (Even their releases aren’t in binaries.)

I might be wrong but I think that Blender 2.5 only uses the system FFMPEG for building Blender, not running it. So don’t worry about compiling your own FFMPEG.

@loopduplicate, yes it may not be necessary depending on what someone wants out of Blender + FFMPEG, but depending on platform FFMPEG ‘stable’ can be rather old. OSX is one of the worst platforms for FFMPEG I think??

To complicate matters Blender relies on FFMPEG to do the YUV -> RGB colourspace conversion when video files are imported but FFMPEG does a bad job of it, re swsscale.

So state of play I think unless things have moved on significantly is that only progressive video sources pass into blender without luma scaling but only if you have a very recent FFMPEG build, ie SVN.

Interlaced sources still get luma scaled and best to import those via something like AVISynth to do the YUV -> RGB conversion.

A bit protracted but really depends on what OP is requiring. :slight_smile:

loop as someone who builds blender on windows, what’s the possibility of you building with svn FFMPEG and AVISynth support switched on in FFMPEG?

Actually I got the same problem but on Ubuntu Linux. Will post about the build later on. Problem occurs with progressive source, I dont even have any interlaced material…

Yes the ‘moire’ or whatever it can be described as happens regardless of progressive or interlaced with older FFMPEG builds like ‘stable’ in the Ubuntu tree. :-). There’s a bug report on the 2.5 tracker about the moire from sometime ago. But resolved with using svn build of FFMPEG.

I got absoluted p-ssed off with trying to keep FFMPEG and Blender 2.5 built from source on Linux for testing trying to keep a localised ‘svn’ and ‘stable’ system FFMPEG with other apps from the repositories then failing to work. Scons paths for specifying localised FFMPEG not working, various patches to allow multiple FFMPEG builds not seeming to work. So I forgot the whole thing and instead use a PPA Ubuntu repository called ‘Cutting Edge Multimedia’

You end up having to remove all traces of existing FFMPEG before adding the PPA but then you get upto date builds of various packages like x264, FFMPEG, VLC simply. Works so far. :slight_smile:

@yellow, what do you reccommend if I’d want to continue vid editing in 2.49? (I have a bunch of projects piled up and learning 2.5 while not even all features are implemented might not be the best idea right now.)

I’m still not clear what would solve my problem in 2.49. Do I need to compile blender, FFMPEG, or both? (If any?) And where could I find step by step instructions on how to do that? Thanks.

Eckie, I don’t really know OSX or whether Blender for OSX has FFMPEG binaries included like Windows. But if Blender on OSX uses system FFMPEG then I guess the only way to use 2.4xx is to get a more recent build or compile blender using latest FFMPEG?

I think the problem you have with 2.4x is it is expecting one thing and the version of FFMPEG you have is delivering another.

Really needs someone familiar with OSX or with knowledge of the build process.

Thanks yellow for the help. I hope someone with OSX experience can help me out. (If anyone familiar with OSX is reading this, please leave a message!)

Meanwhile I’ll try to find a way to compile svn FFMPEG.

Hey guys,

I installed FFMPEG (with help from my roommate) but the problem isn’t fixed in blender 2.49b yet.
Is there a way to see which FFMPEG version blender is using? We can’t seem to find any config file or ways to see which version is being used.


Eckie, compile 2.49b from source, but first uncomment the two lines in the file under the FFMPEG settings and you’ll need a number of dev files first like libavformat-dev, libavdevice-dev, libswscale-dev, libavdevice-dev, libavutil-dev, etc then compile 2.49b and it will then be up to date.

Thanks for the advice yellow, but I really don’t have the technical skill to make that happen. I’m installing Final Cut now and am hoping for a quick full release of blender 2.5. (Which isn’t outputting any video at all at the moment.)

the ‘problem’ is called a compression artifact. It is caused by the codec trying to compress the video file size. it has nothing to do with osx or Blender or even caused by ffmpeg. it is simply the quality that you have to sacrifice as the tradeoff for file size. Compression artifacts are irreparable. I discuss compression artifacts and how to deal with them in chapter 4 of my book

No it was a Blender / FFMPEG bug, nothing to do with compression artifacts.

And Eckie makes it clear above that the problem went away with the same source material after it was suggested he try recent 2.5 builds and newer FFMPEG.