Topics

https://github.com/dnglab/dnglab

This is a new DNG conversion tool for linux!

This is not my repo, but I am excited for development!

I thought I'd mention it for any devs who want another project to work on! There is a need for Cinema DNG support, if anyone has knowledge to contribute!

Hey all!

I've recently purchased a Sigma FP and am shooting UHD 12bit RAW cDNG. I use my Canon 5DIII with Magic Lantern shooting RAW as a B-Cam. The Sigma FP does not apply lossless LJ92 compression out of the camera, and I love that MLV APP allows me to export Lossless DNG for my Canon MLV RAW. I have processed the Sigma FP files with Adobe DNG Converter to apply lossless compression, but I lose all cinemaDNG-associated metadata in the process (timecode, color matrix, profile hue sat map, and bit depth.) Also, the audio must have embedded timecode, and thus does not sync with my Adobe-DNG-converted sequence. TLDR, Adobe DNG Converter does the trick to apply lossless compression, but comes with many caveats for cDNG.

Thus I'm determined to learn enough coding to write a script that can import cDNG, apply lossless LJ92 compression, and thats it. Leaving all metadata intact, and no conversion to higher bit depths.

I found this to be helpful in understanding the compression: https://thndl.com/how-dng-compresses-raw-data-with-lossless-jpeg92.html

I've spoken with a member of this forum on tips how to do this. The following was their instructions:

"First you would need to make a python extension allowing you to use the LJ92 library: https://github.com/ilia3101/MLV-App/tree/09a726ef66f693f29dd551534f7340cadb1c1955/src/mlv/liblj92. MlRawViewer had code for this, but it is for Python2 (now deprecated) and includes extra functions for bayer->RGB conversion. You would need to start from this file: https://bitbucket.org/baldand/mlrawviewer/src/master/bitunpack.c and cut it down to just the LJPEG parts + update for Python3 as required.

Python setup.py file: https://bitbucket.org/baldand/mlrawviewer/src/master/setup.py At this point I would also suggest updating the LJ92 to the version in mlv-app, but it may have some slight interface changes. Then you will need to update the DNG.py file for Python3: https://bitbucket.org/baldand/mlrawviewer/src/master/DNG.py After that you should have the needed parts to make a script that can read existing cDNG files, compress them, and write out a copy."

I have started a repo here: https://github.com/devonstanczyk/Digital-Negative-Lossless-Compression.git

I am very new to this, so please any help/collaboration is appreciated! Also, if I'm stepping on any toes, please know it's unintentional and let me know!

Thanks all!

This is a total newb question, but I just need some help to get started on the right foot:

What app can I use to view the "code" that makes up a .CR2 or .DNG file?

Context: http://lclevy.free.fr/cr2/
That is a link that provides an explanation of the code inside a .CR2 file. BUT I cannot figure out how to open my own .CR2 files to view the "code."

What apps allow me to do this on macOSX?

Thanks so much!

For those of us who are new, can a veteran of the forum provide a TLDR explanation of how ML achieves RAW video? And in layman's terms as much as possible?

I think I recall someone eventually gained access to EDMAC (is that the right acronym?) How did we get there, and then what followed?

I've received a .DNG sequence from a coworker, and the files are incredibly small (like 200kb-ish a frame.) My suspicion is that they exported a .JPG sequence, and then converted the .JPG's to .DNG (which apparently you can do that???)

How can I check if a .DNG is really raw data? Can I open in a text editor? Is there a utility that makes it easy?

Thanks all!

On the 5DMKIII, ssing the experimental 10/12-bit RAW video: "magiclantern-raw_video_10bit_12bit.2019Mar24.5D3123" build.

I can get 1920x1280 (3:2) 12bit continuous RAW/.MLV with sound

That said, on my 5DmkIII, it's getting the full width of the sensor (I believe? Yes?).

Is it pixel binning/skipping to get the full width? Or is it super sampling the whole sensor?

Also, with the "mlv_snd" module, do I still get sound if I'm doing a FPS override at an even 24.00fps? (FPS override says that it disables sound.)

Thanks all!