[FFmpeg-devel] Add support for LJ92 compressed MLV files, attempt 02

[South East]

Thanks for taking a look!

On Tue, 29 Oct 2024 at 15:25, Tomas Härdin <git at haerdin.se> wrote:
> > -#define MLV_CLASS_FLAG_DELTA 0x40
> >  #define MLV_CLASS_FLAG_LZMA  0x80
> > +#define MLV_CLASS_FLAG_DELTA 0x40
> > +#define MLV_CLASS_FLAG_LJ92  0x20
>
> This hunk could be simpler if you didn't move MLV_CLASS_FLAG_DELTA

This preserves the order of flags in the code that creates MLV files:
https://github.com/reticulatedpines/magiclantern_simplified/blob/f7a1df28c52eb7e1725b078a5fd2c4dedb3bac85/modules/raw_video/mlv_rec/mlv.h#L32
I don't care a large amount, and can change it, but being consistent
has some value.

> Not sure how Bayer in JPEG works so can't really comment more on patch
> 1.

I don't know how Bayer in JPEG works either.  I'm not sure if you mean
the file format, or the data compression standards.  While MLV can use LJ92
compression applied to Bayer data, there are no JPEG files involved.

The existing mjpeg LJ92 support, that I'm building on, came from this work:
https://velocityra.github.io/gsoc-2019/

> Patch 2 looks simple enough.

Good, I was hoping that one would be.