MLV App 1.14 - All in one MLV Video Post Processing App [Windows, Mac and Linux]

[IDA_ML]

Hello all,

With this post, I would like to make a suggestion for a new feature which, if implemented in MLVApp, could be a life savior for all those users that sooner or later may end up with corrupt .MLV files that fail to open due to the "Header missing" issue.  It seems to happen quite often.

Recently, I filmed a wedding on the 5DMkIII using the Lexar Pro x1066 CF card.  Format was 10-bit LL,1360x2296 anamorphic with sound.  After the wedding, I transferred the files from the card to my laptop using a card reader and found that just a few of them would open fine in MLVApp 1.8, the remaining 68 files would fail to open due to file corruption - "Header missing" message.  MLVFS would produce an empty folder with the same name as the corrupt file itself.  A second attempt to reload the files from the card ended up with a message "Card cannot be accessed" and a prompt to format the card.  Obviously, the card was corrupt.  All I could do was ask A1ex for help and he suggested that I should use an application he wrote, called mlv_dump_bruteforce.exe, that attempts to skip invalid headers:

https://a1ex.magiclantern.fm/bleeding-edge/mlv-recover/mlv_dump_bruteforce.exe

Usage:

mlv_dump_bruteforce.exe M16-1437_Corrupt.MLV -o M16-1437_Recovered.MLV

where in this case M16-1437_Corrupt was the name of the MLV file missing its header.  This worked for me quite nicely and I was able to open the corrupt files one by one in MLVFS.  Later on, A1ex suggested the following command line:

----------------------------------------------------------------
%F in (*.MLV) do mlv_dump_bruteforce.exe %F -o R-%F
----------------------------------------------------------------

that, after placing mlv_dump_bruteforce.exe in the directory with the corrupt files, fixed all of them in a fast batch process.  Using MLVFS and DaVinci Resolve, I could work with the recovered files as usual.  This really saved my life!  Thank you so much, A1ex! Unfortunately, MLVApp still fails to open them after recovery.

So, my suggestion to the MLVApp developers is, if possible, to implement mlv_dump_bruteforce into the next version of the software.  If there are corrupt MLV files in the working directory, MLVApp should recognize them and suggest to batch recover them with the above command line.  Then it should open them and allow corrections and processing as usual. I am sure, many users that experience the same problem as described above will greatly appreciate that.

Please let me know if this is doable.  If yes, I can upload one of my corrupt files, so you can see if you can get MLVApp to recover and work with it.

[Walter Schulz]

----------------------------------------------------------------
%F in (*.MLV) do mlv_dump_bruteforce.exe %F -o R-%F
----------------------------------------------------------------

Code: [Select]

For %F in (*.MLV) do mlv_dump_bruteforce.exe %F -o R-%F

[DeafEyeJedi]

Please let me know if this is doable.  If yes, I can upload one of my corrupt files, so you can see if you can get MLVApp to recover and work with it.

Should be doable. Indeed, this should be a high priority. Thanks for sharing your story @IDA_ML!

[masc]

mlv_dump_bruteforce is a program (if I understood right) and not MLVApp. So we need the information (better: code) what this program does. Then we can see if it is possible to integrate this code into MLVApp. For using a commandline it is way easier to write a batch file.

How does MLVApp fail to open those recovered files? Crash? Or messagebox? If it brings a messagebox, this will have reasons.

[IDA_ML]

Masc,

When trying to open a corrupt MLV file with MLVApp, I get the message:

"File header is missing, invalid MLV"

A1ex sent to me this link that reveals the basic idea.  I don't understand anything of it but it may be helpful to you:

https://www.magiclantern.fm/forum/index.php?topic=22822.msg206290#msg206290

Maybe, he could ellaborate more on that.

@Waler Schulz

Thanks for correcting the error in the command line code.

[masc]

When trying to open a corrupt MLV file with MLVApp, I get the message:
"File header is missing, invalid MLV"

Really? For the recovered file you get this? Then the recovery can't be 100% correct.

[IDA_ML]

No, I get the above message when I try to open a corrupt file.  When I do the same with a bruteforce recovered file, MLVApp crashes with the message:

"MLVApp has stopped working"

MLVFS works fine with recovered files though.

[IDA_ML]

Masc,

I have just uploaded one of my corrupt files for you to see what is going on:

https://we.tl/t-S8XJnBt4bQ

[masc]

When I do the same with a bruteforce recovered file, MLVApp crashes with the message:
"MLVApp has stopped working"

This file would also be very interesting. MLVApp should never crash. So I would like to do some research here.

[ilia3101]

MLVApp should never crash.

I will admit this made me chuckle

[2blackbar]

Is there a plan to add gamma curves for correcting or subsitute already exists ? I tinkered with luminosity but its a bit different
https://en.wikipedia.org/wiki/Gamma_correction

[masc]

Is there a plan to add gamma curves for correcting or subsitute already exists ?

It already exists in the branches for better/improved processing. When it is finished completely it will be merged into master branch.

[DeafEyeJedi]

When it is finished completely it will be merged into master branch.

Fantastic to hear! 

[2blackbar]

Great , is there a reason why were locked out of correcting a lot of sliders when changing to srgb or rec709 from tonemapped which is default ? When i enable correcting by ticking "allow creative adjustments" then footage becomes a lot darker.

[masc]

Great , is there a reason why were locked out of correcting a lot of sliders when changing to srgb or rec709 from tonemapped which is default ? When i enable correcting by ticking "allow creative adjustments" then footage becomes a lot darker.

Yes, there is a reason. Using curves or other adjustments won't bring correctly converted footage. But it would be needed, if you e.g. apply LUTs in your NLE. So it is disabled by default. You can enable it ("Allow creative adjustments") and see what the curves (which are normally enabled for other profiles) do with your footage. Use dark/light strength/range and lighten to adjust your footage as you like.

[2blackbar]

From what i see if i enable creative adjustment and move dark strength to 0 then footage will be fine and not so dark anymore so maybe theres no need to lock eveyrhing when in BMD , just force dark strength to 0 and enable everything else.

[ilia3101]

set dark strnegth to zero and u wont have any darkness issue, then adjust it to your liking

Yes, there is a reason. Using curves or other adjustments won't bring correctly converted footage. But it would be needed, if you e.g. apply LUTs in your NLE. So it is disabled by default. You can enable it ("Allow creative adjustments") and see what the curves (which are normally enabled for other profiles) do with your footage. Use dark/light strength/range and lighten to adjust your footage as you like.

I guess it is pretty rare for anyone to actually want completely accurate rec709 or sRGB footage, only with LOG spaces do people want that. Even cameras when shot in their own "rec709" modes tend to have a special curve for better highlight roll-off, and slight colour tweaks to the manufacturer's preference, so it's not truly rec709 standard. I think rec709 mode in MLV App is not that useful. Normal tonemapped mode is still rec709, just with a lighter gamma and tonemapped curve, but once you've adjusted it and made it right, it is still interpreted as rec709 by all other video software, so all MLV App output is basically rec709 footage unless you use a LOG profile.

[2blackbar]

Also HSL would be nice with one more : Saturation vs. Luminance

[masc]

Interesting @2blackbar. Thanks. You mean Luminance vs. Saturation (small difference in text, big difference in results)  Always wanted to see what you can do with this, because I remember it was already asked a time ago.
Should be doable.

[2blackbar]

Yeah Youre right, also this guy has a lot of interesting stuff to say about color correcting and grading in his videos, i tend to correct most of the time because i already love how tonemapped in MLVApp looks like.
Does tonemapped have gamma curve that makes it look more like film than standard or r709 ? Id like to take control of that curve myself thats why i asked about it.

[masc]

Does tonemapped have gamma curve that makes it look more like film than standard or r709 ? Id like to take control of that curve myself thats why i asked about it.

It has a gamma curve, yes. Some minutes ago the branch was merged to master, where you can adjust gamma as you like. For now: to be compiled.

[2blackbar]

Fantastic, its getting better and better

[Luther]

It has a gamma curve, yes. Some minutes ago the branch was merged to master, where you can adjust gamma as you like. For now: to be compiled.

Hoah! I'll compile this week and do some tests!

[Danne]

Very nice addition with the gamut stuff and the processing presets. Seems to work very good too.
Probably a reason for not being able to alter the set up once applied but is it possible to change curves etc and still have the starting point for example reinhardt/rec709? Right now I can allow adjustments when selecting Allow creative adjustments but this takes me to a whole new view? Gamma is changed etc. Would be nice to modify exactly from starting point.

[ilia3101]

Right now I can allow adjustments when selecting Allow creative adjustments but this takes me to a whole new view? Gamma is changed etc.

It's because of the default dark strength value of 20, just set it to zero. There is no new view, no changed gamma, there's nothing going on that you can't control in MLV App (unless its a bug).

I agree that that switching moment is confusing in some profiles, I noticed yesterday. Feels a bit like rawtherapee ux. I am very strongly considering changing the default settings in MLV App, maybe having 0 dark strength by default.