Fix of the Flash description for Flash == OFF

[Gorbush]

For the case mentioned in #354
The case when the value is 0x10 - the description should say no Auto - as it is enforced to be OFF

[drewnoakes]

Do you have a reference for this change? (On phone right now.)

[Gorbush]

The reference is here:
Hi,

sorry missed this email.
By reference did you mean why I think this change is right?

Here is the clarification:
com/drew/metadata/exif/ExifDirectoryBase.java:333
Basing on the description of this field

/**
 * 0x0  = 0000000 = No Flash
 * 0x1  = 0000001 = Fired
 * 0x5  = 0000101 = Fired, Return not detected
 * 0x7  = 0000111 = Fired, Return detected
 * 0x9  = 0001001 = On
 * 0xd  = 0001101 = On, Return not detected
 * 0xf  = 0001111 = On, Return detected
 * 0x10 = 0010000 = Off
 * 0x18 = 0011000 = Auto, Did not fire
 * 0x19 = 0011001 = Auto, Fired
 * 0x1d = 0011101 = Auto, Fired, Return not detected
 * 0x1f = 0011111 = Auto, Fired, Return detected
 * 0x20 = 0100000 = No flash function
 * 0x41 = 1000001 = Fired, Red-eye reduction
 * 0x45 = 1000101 = Fired, Red-eye reduction, Return not detected
 * 0x47 = 1000111 = Fired, Red-eye reduction, Return detected
 * 0x49 = 1001001 = On, Red-eye reduction
 * 0x4d = 1001101 = On, Red-eye reduction, Return not detected
 * 0x4f = 1001111 = On, Red-eye reduction, Return detected
 * 0x59 = 1011001 = Auto, Fired, Red-eye reduction
 * 0x5d = 1011101 = Auto, Fired, Red-eye reduction, Return not detected
 * 0x5f = 1011111 = Auto, Fired, Red-eye reduction, Return detected
 *        6543210 (positions)
 *
 * This is a bitmask.
 * 0 = flash fired
 * 1 = return detected
 * 2 = return able to be detected
 * 3 = unknown
 * 4 = auto used
 * 5 = unknown
 * 6 = red eye reduction used
 */

Auto is everywhere where bit is set 0x10 but requires that the lower 4 bits
are not zero:

 * 0x10 = 0010000 = Off

 * 0x18 = 0011000 = Auto, Did not fire
 * 0x19 = 0011001 = Auto, Fired
 * 0x1d = 0011101 = Auto, Fired, Return not detected
 * 0x1f = 0011111 = Auto, Fired, Return detected

 * 0x59 = 1011001 = Auto, Fired, Red-eye reduction
 * 0x5d = 1011101 = Auto, Fired, Red-eye reduction, Return not detected
 * 0x5f = 1011111 = Auto, Fired, Red-eye reduction, Return detected

[drewnoakes]

Thanks for following up. This looks great.

[Gorbush]

Hi, sorry missed this email. By reference did you mean why I think this change is right? Here is the clarification: com/drew/metadata/exif/ExifDirectoryBase.java:333 Basing on the description of this field /** * 0x0 = 0000000 = No Flash * 0x1 = 0000001 = Fired * 0x5 = 0000101 = Fired, Return not detected * 0x7 = 0000111 = Fired, Return detected * 0x9 = 0001001 = On * 0xd = 0001101 = On, Return not detected * 0xf = 0001111 = On, Return detected * 0x10 = 0010000 = Off * 0x18 = 0011000 = Auto, Did not fire * 0x19 = 0011001 = Auto, Fired * 0x1d = 0011101 = Auto, Fired, Return not detected * 0x1f = 0011111 = Auto, Fired, Return detected * 0x20 = 0100000 = No flash function * 0x41 = 1000001 = Fired, Red-eye reduction * 0x45 = 1000101 = Fired, Red-eye reduction, Return not detected * 0x47 = 1000111 = Fired, Red-eye reduction, Return detected * 0x49 = 1001001 = On, Red-eye reduction * 0x4d = 1001101 = On, Red-eye reduction, Return not detected * 0x4f = 1001111 = On, Red-eye reduction, Return detected * 0x59 = 1011001 = Auto, Fired, Red-eye reduction * 0x5d = 1011101 = Auto, Fired, Red-eye reduction, Return not detected * 0x5f = 1011111 = Auto, Fired, Red-eye reduction, Return detected * 6543210 (positions) * * This is a bitmask. * 0 = flash fired * 1 = return detected * 2 = return able to be detected * 3 = unknown * 4 = auto used * 5 = unknown * 6 = red eye reduction used */ Auto is everywhere where bit is set 0x10 but requires that the lower 4 bits are not zero: * 0x10 = 0010000 = Off * 0x18 = 0011000 = Auto, Did not fire * 0x19 = 0011001 = Auto, Fired * 0x1d = 0011101 = Auto, Fired, Return not detected * 0x1f = 0011111 = Auto, Fired, Return detected * 0x59 = 1011001 = Auto, Fired, Red-eye reduction * 0x5d = 1011101 = Auto, Fired, Red-eye reduction, Return not detected * 0x5f = 1011111 = Auto, Fired, Red-eye reduction, Return detected

…

On Mon, Jul 30, 2018 at 2:52 PM, Drew Noakes ***@***.***> wrote: ***@***.**** commented on this pull request. ------------------------------ In Source/com/drew/metadata/exif/ExifDescriptorBase.java <#356 (comment)> : > @@ -844,7 +844,8 @@ public String getFlashDescription() sb.append(", return not detected"); } - if ((value & 0x10) != 0) + // If 0x10 is set and the lowest byte is not zero - then flash is Auto + if ((value & 0x10) != 0 && (value & 0x0F) != 0) sb.append(", auto"); Do you have a reference for this change? (On phone right now.) — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#356 (review)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAsM97K27TQuEoUrr-qUtDo_plZtkZ84ks5uL4AGgaJpZM4VnDit> .

[drewnoakes]

Looks like we have the same issue in the .NET version, if you want to take a stab at it:

https://github.com/drewnoakes/metadata-extractor-dotnet/blob/master/MetadataExtractor/Formats/Exif/ExifDescriptorBase.cs#L940