Just a quick update to a previous post regarding 8bit to 16bit conversion. Previously http://blendervse.wordpress.com/2011/09/16/8bit-video-to-16bit-scene-referred-linear-exrs
The main issue with the process is it’s memory intensive and the way avs2yuv works by requiring the whole video in memory before starting processing rather than taking a frame of video at a time into memory.
Previously it would be necessary to use the Avisynth ‘Trim’ command and split a video into managable frame range chunks via numerous avs scripts and process each script in a batch process all based on available processing power and RAM.
A while ago the main AvsPmod developer, vdcrim kindly created a script based on my needs for an automated approach using AVSPmod’s python based macro authoring feature. The Pipe To RGB macro is downloadable here: (Right Mouse Button Save Link As)
And AvsPmod from here:
So now a video can be loaded into AvsPmod and the whole lot piped to Imagemagick as 16bit RGB via an automated macro which can be set to split video frame ranges by ‘Steps’, ‘Time’ or ‘Intervals’.
Additionally AvsPmod’s bookmarking option can be used to set scene changes to suit the user and the Pipe To RGB macro will not only batch in ‘Steps’, ‘Time’ or ‘Intervals’ but then subdivide the output into sequentially named ‘Scene_001′ folders from the bookmarks.
There’s also an option to add additional Imagemagick processing arguements and set a destination folder and sequential file name prefix.
And why convert to RGB and at 16bit? Perhaps test using the files in the zip below to see if you think it’s worthwhile after editing before color grading and finishing.
Here’s a link to a zip containing 16bit frames from a 8bit Canon DSLR MOV.
And a quick illustration of one basic RGB Curves adjustment in Blenders OpenCL Nodal Compositor on the original 8bit MOV file and the 16bit output options as in the Frames.zip above.
Original 8bit MOV (Above)
Quick 8 to 16bit Conversion, with no further processing. (Above)
Quick 8 to 16bit Conversion with addition of Smoothing Gradients at 16bit with no further processing. (Above)
Using MCTDmod Avisynth script for Motion Compensated Temporal processing at 16bit, including Denoise, Stabilizing shimmer in flat areas, Enhancement with GradFun2DBmod to reduce banding and blockiness and Adaptive Luma Sharpening using LSFMod. MCTDmod is processor intensive, there is an option to use the GPU for some of the script components.
One option missing I felt was the ability to extract ‘Hero’ frames at 16bit, well vdcrim has kindly updated the Pipe To RGB macro today to include the feature to pipe just the frames on bookmarks to Imagemagick again as 16bit RGB using the process from the 8 to 16bit EXR post, so now as the 8 to 16bit conversion process can take some time :-) depending on processing involved, first we can set bookmarks for ‘hero’ frames for each scene in a movie or those most represntative of each scene, pipe those singular frames to imagemagick and use the 16bit output in Blender to start ‘look’ developement for the grading process whilst we wait for the full conversion of the whole movie to 16bit image sequences to take place.