[Cin] MLRAW

[edouard chalaron]

Point was to avoid huge intermediate files, I think, and save some
time, too.
But well, ffmpeg apparently handles those files a bit wrongly - for
example by 
default it tries to stuff data into just rgb24 - probably ok for
display, but 
whole point of those huge  raw files was additional color precision
(and 
avoidance of h264 artefacts).

Agreed but there is a trade off between time and storage.Storage
getting cheaper by the minute, I choose to use storage, on RAID0 or
SSDs
I read that you want to avoid big files and also avoid h264 artefacts,
fair enough, I think everyone would like it.Truth is ... I don't
believe it's that possible. Exporting Raw to H264 for editing is not a
good idea anyway as you mentionnedAnd getting Raw to a readable format
is not fast and it has to be done at some at some stage.
Unless GG comes up with another miracle ! :-D
So which codec then .. PRORES does handle 10 bits and up 4444, which is
pretty good for color resolution.DNX was better but more limiting and
not sure if it handles more than 24with PRORES you can throw any
geometry, frame rate, color depth or about
You can also export in TIFF either 24 or 48 bits with ffmpeg (even more
than 48 actually), depending on your source.Cin is very fast to open a
sequence of TIFF files.Then you are sure that you are not loosing any
color info, PRORES still being a (slightly) lossy codec.
I dont think there is any point exporting in h264 unless you do a
lossless, but then ... export in TIFF files, faster / better. A bit of
a Neanderthal solution, I agree, but reliable.
As for ffmpeg reading the stream, ffmpeg won't find out, it's raw
video, there is zero info as per what ffmpeg should read, hence the
command line aboveIn my case it's either rgbXX or bgrXX (I think there
is more than just these 2 though) As I see it, trying to incorporate
raw video in Cin* is reinventing the wheel.There is already the tools
needed for conversion and Cinelerra is an editing software not a video
converter.
Just sharing my experience / needs / ideas etc ... CheersEd


> from  https://thndl.com/life-without-artifacts.html
> 
> ------quote---------
> So, I've taken the plunge and moved to RAW. I have hundreds of
> gigabytes 
> (seriously) of artifact-free footage recorded in the latest Magic
> Lantern MLV 
> (RAW v2) file format. Now what. How do I watch it?
> The tools seem to be lagging a bit behind here. The start of most
> "workflow" 
> right now is to use the mlv2dng tool to create individual files for
> each raw 
> frame in the video in Adobe's widely understood DNG format.
> If you have a Mac or Windows, those thousands of DNGS can then be
> imported 
> either into a tool like Adobe After Effects, or DaVinci Resolve
> (which 
> currently needs an NVIDIA GPU). Those allow fine control of colour
> mapping 
> (usually called "grading") and other effects using the full colur
> resolution, 
> before you finally convert the result into a compressed video.
> If you're using Linux, like me, different options are needed. A not-
> so-quick but 
> dirty way to preview the video is to use a couple of commands like:
> dcraw -T *.dng
> ffmpeg -i %6d.tiff -vcodec mjpeg -r 25 -q:v 1 video.avi
> 
> This can still take a little while to churn through the images, and
> then ffmpeg 
> doesn't always seem to do a great job mapping the colour ranges. But
> it works. 
> Only don't forget to delete all the intermediate files afterwards
> otherwise you 
> will have quintupled your file space.
> This approach quickly got tedious for me after working with more than
> a few 
> videos. What I really wanted was something that could just play all
> the raw 
> videos directly like any other video format, so I could decide which
> ones 
> deserved further editing.
> 
> --------------end of quote----
> 
> quote above talks about  MLV files specifically
> 
> 
> > Depending on the machine bgr24/48 may need to be rgb24/48. I use
> > either
> > of them depending on the camera I use
> > Only if my assumption of the rawvideo concept is what we are
> > talking
> > about here !CheersEd
> > 
> > On Tue, 2019-02-12 at 12:53 -0700, Phyllis Smith wrote:
> > > This morning GG had time to look at this.  (BTW, he is not much
> > > for
> > > reading or writing email so I have to let him know and then type
> > > in
> > > his response, so sometimes I do not get it all conveyed
> > > correctly).
> > > 
> > > When I initially read only a few of the 86 pages, I searched for
> > > some
> > > download MLV examples and downloaded a couple from one place and
> > > then
> > > 1 from where Andrew mentioned.  Apparently ffmpeg can load them
> > > into
> > > cinelerra and the Video compression in Info is rawvideo, but of
> > > course they look awful as is (maybe a proper LUT would solve
> > > this?).
> > > 
> > > We also checked to see if "dcraw" of Dave Coffin handles this raw
> > > format as that is his area of expertise and saw no reference on
> > > his
> > > web site concerning Magic Lantern.  But we still tried using
> > > Cinelerra's probe order in Settings to see whether his included
> > > program handled it.  It did not.
> > > 
> > > Bottom line is that if there is ever a user who really needs to
> > > be
> > > able to handle MLV files in cinelerra, gg could see about doing
> > > that
> > > and will keep this in mind.   gg/Phyllis
> 
> 
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