Magic Lantern Forum

Using Magic Lantern => Raw Video => Topic started by: qqqavi on April 07, 2017, 09:14:40 AM

Title: Changing black levels doesn´t work anymore
Post by: qqqavi on April 07, 2017, 09:14:40 AM
Hi everyone.

For some reason, changing the black level with mlv_dump doesn´t work anymore. It did work before.



I always used this command as in the thread http://www.magiclantern.fm/forum/index.php?topic=11664.0:
mlv_dump --black-fix=2048 -o out.mlv in.mlv

It creates a new mlv, but with no changes at all. It drives me crazy....

If I export to .dng (Raw2cdng) and I use the exiftool command -BlackLevel=2048 input.dng , I get the ¨0 images updated¨ message. Someone knows why?

Here you can download a .dng file:
https://file.town/download/m1smv1v2a3sck3qh0x93ji5kd

Is there  way to fix this?

I´m on a Windows 8.1 machine.
Thank you.

Title: Re: Changing black levels doesn´t work anymore
Post by: a1ex on April 07, 2017, 09:39:29 AM
Can you upload a small MLV so others can try reproducing the issue?

If you cannot change the black level on a DNG, it's a problem with the DNG converter (and you should report it in the relevant thread).
Title: Re: Changing black levels doesn´t work anymore
Post by: qqqavi on April 07, 2017, 10:32:39 AM
Hi there.

I´ve just upload a mlv  file   ( 134MB - that´s the smallest one I  have) with the wrong  black levels.

You can download it here:

https://expirebox.com/download/f56643f020df06a01ae63f07756d9f43.html

As I said, I´m not able to change the black level with mlv_dump anymore, no matter what value I put. A new mlv is created, no errors, just that the new mlv looks exactly the same.  It never happened to me before.

Thank you. 

Title: Re: Changing black levels doesn´t work anymore
Post by: Danne on April 07, 2017, 10:45:32 AM
Black level 2289 and it works perfectly well to change it to 2048 in mlv_dump over here.
Title: Re: Changing black levels doesn´t work anymore
Post by: qqqavi on April 07, 2017, 10:59:28 AM
How did you do it?

My workflow is (on Win):

1.  I copy the mlv_dump.exe on the same folder as the mlv file
2. I run ¨cmd¨ to open the command window
3. Go to the mlv file location (e.g. C:\Folder>)
4. I run the c:\Folder>mlv_dump --black-fix=2048 -o b.mlv m01-1526.mlv

That´s  the  message I get after, however the new mlv looks the same:

Mode of operation:
   - Input MLV file: 'm01-1526.mlv'
   - Setting black level to 2048
   - Rewrite MLV
   - Output into 'b.mlv'
File m01-1526.mlv opened
File m01-1526.m00 not existing.
Processing...
Reached end of chunk 1/1 after 264 blocks
Processed 46 video frames
Done
Title: Re: Changing black levels doesn´t work anymore
Post by: Danne on April 07, 2017, 11:04:24 AM
Don,t think you can rewrite the MLV file with new black level. Try:
mlv_dump --dng --black-fix=2048 m01-1526.mlv
Title: Re: Changing black levels doesn´t work anymore
Post by: qqqavi on April 07, 2017, 11:24:14 AM
It worked!!!

The problem was that on this thread http://www.magiclantern.fm/forum/index.php?topic=7122.0
there are two links to download the mlv_dump:


BAD VERSION where it says WIN ONLY (didn´t worked for me): mlv_dump: most recent nightly download page. (binary for WINDOWS only)

GOOD VERSION: mlv_dump: or here (binaries for WINDOWS, LINUX and OSX)

I´ve tried the second  one and it worked. I don´t know why, perhaps the two .exe are different. So frustrating.

Thank you.
Title: Re: Changing black levels doesn´t work anymore
Post by: Danne on April 07, 2017, 11:30:31 AM
I,d also recommend this for some beefed up metada and cdng output.
http://www.magiclantern.fm/forum/index.php?topic=18975.0
Title: Re: Changing black levels doesn´t work anymore
Post by: qqqavi on April 07, 2017, 11:36:29 AM
Thank you very much  for your time and support.
Best.