thumbnail offset

Started by jvance4, May 21, 2012, 03:21:52 PM

Previous topic - Next topic
Print
Go Down Pages1
User actions

jvance4

May 21, 2012, 03:21:52 PM
v8.92 is consistently reporting thumbnail offset different than XnView v1.98.8. i.e exiftool reports offset of 1194 where XnView reports it as 1182.  The difference of 12 is consistent.
Which is correct?

Jack

Phil Harvey

#1
May 21, 2012, 08:24:45 PM
Of course, ExifTool is correct. ;)

But so is XnView.

It all depends on your point of view.

The offset reported by ExifTool is the byte offset of the ThumbnailImage from the start of the file.

The offset reported by XnView is the byte offset of the ThumbnailImage from the start of the JPEG APP1 EXIF segment.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

jvance4

#2
May 22, 2012, 10:21:03 AM
Thank you. I have a couple more anomolies that perhaps you could explain.
ExifTool v8.75 reports only the last 9 characters of file permissions and does not report position 0 (left most) of (d, l or -). Is this because exiftool only parses "regular" files and not directories or link files, so no need for the position 0 character?

For "Aperture Value and Max Aperture Values" in my example exiftool v8.75 is reporting "2.6". FTK Lab v3.4 is reporting "88/32" or 2.75.  Why the .15 difference?

Jack

Phil Harvey

#3
May 22, 2012, 11:42:07 AM
Hi Jack,

Quote from: jvance4 on May 22, 2012, 10:21:03 AM
Thank you. I have a couple more anomolies that perhaps you could explain.
ExifTool v8.75 reports only the last 9 characters of file permissions and does not report position 0 (left most) of (d, l or -). Is this because exiftool only parses "regular" files and not directories or link files, so no need for the position 0 character?

Until now I haven't thought about this.  From the "ls" man page:

           b     Block special file.
           c     Character special file.
           d     Directory.
           l     Symbolic link.
           s     Socket link.
           p     FIFO.
           -     Regular file.

I'm not sure about some of these, but maybe only "-" and "l" would be appropriate for the files that exiftool reads.  However, I haven't had anyone mention that they would have a use for this information.

QuoteFor "Aperture Value and Max Aperture Values" in my example exiftool v8.75 is reporting "2.6". FTK Lab v3.4 is reporting "88/32" or 2.75.  Why the .15 difference?

2.75 is the Apex value that corresponds to an FNumber of 2.6.  ExifTool converts ApertureValue and ShutterSpeedValue from Apex units to the more familiar units when reading.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

jvance4

#4
May 23, 2012, 08:53:20 AM
Good Day Phil - does ExifTool parse GPS info?


Jack

Phil Harvey

#5
May 23, 2012, 09:00:07 AM
Yes.
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

jvance4

#6
May 23, 2012, 04:11:09 PM
Using Samsung SGH-T939 reports "Aperture Value" of 2.97 and "Max Aperture" of 2.80.  ExifTool v8.75 reports "Aperture Value" and "Aperture" of 2.8 and "Max Aperture Value" of 2.6.  Why the deltas?

Jack

Phil Harvey

#7
May 23, 2012, 07:32:28 PM
Hi Jack,

Is this the same question that I just answered 2 posts back?

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

jvance4

#8
May 25, 2012, 08:59:36 AM
See data below for 2 files and why are File ID and Creation Date zeros? 

Thank you,
Jack

ExifTool Version Number         : 8.75
File Name                       : xxxxxxxxx.wmv
Directory                       : /mnt/in/ExifTool/New movie files
File Size                       : 5.8 MB
File Modification Date/Time     : 2012:04:05 20:16:11+00:00
File Permissions                : rw-r--r--
File Type                       : WMV
MIME Type                       : video/x-ms-wmv
File ID                         : 00000000-0000-0000-0000-000000000000
File Length                     : 6075737
Creation Date                   : 0000:00:00 00:00:00Z
Data Packets                    : 1898
Play Duration                   : 0:04:16
Send Duration                   : 0:04:16
Preroll                         : 2000
Flags                           : 0
Min Packet Size                 : 3200
Max Packet Size                 : 3200
Max Bitrate                     : 64 kbps
Image Width                     : 320
Image Height                    : 240
Stream Type                     : Audio
Error Correction Type           : No Error Correction
Time Offset                     : 0 s
Stream Number                   : 2
Audio Codec ID                  : MP3
Audio Channels                  : 2
Audio Sample Rate               : 22050
Video Codec Name                : msmpeg4
Video Codec Description         :
Audio Codec Name                : mp3
Audio Codec Description         :
Image Size                      : 320x240

ExifTool Version Number         : 8.75
File Name                       : zzzzzzzzzz.wmv
Directory                       : /mnt/in/ExifTool/New movie files
File Size                       : 6.8 MB
File Modification Date/Time     : 2012:04:05 20:20:51+00:00
File Permissions                : rw-r--r--
File Type                       : WMV
MIME Type                       : video/x-ms-wmv
File ID                         : 00000000-0000-0000-0000-000000000000
File Length                     : 7089579
Creation Date                   : 0000:00:00 00:00:00Z
Data Packets                    : 2215
Play Duration                   : 0:02:22
Send Duration                   : 0:02:18
Preroll                         : 3100
Flags                           : 2
Min Packet Size                 : 3200
Max Packet Size                 : 3200
Max Bitrate                     : 378 kbps
Encoding Settings               : Lavf52.60.0
Image Width                     : 480
Image Height                    : 360
Stream Type                     : Audio
Error Correction Type           : Audio Spread
Time Offset                     : 0 s
Stream Number                   : 2
Audio Codec ID                  : Windows Media Audio V2 V7 V8 V9 / DivX audio (WMA) / Alex AC3 Audio
Audio Channels                  : 2
Audio Sample Rate               : 44100
Video Codec Name                : wmv2
Video Codec Description         :
Audio Codec Name                : Windows Media Audio V8
Audio Codec Description         :
Image Size                      : 480x360

Phil Harvey

#9
May 25, 2012, 09:19:28 AM
ExifTool will display a creation date of "1970:01:01 00:00:00" as "0000:00:00 00:00:00" because this is time zero for the standard C time functions, and is typically used when the application doesn't store a  value for the time.

Similarly, it seems the application writing these WMV files didn't store a FileID either.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

jvance4

#10
June 01, 2012, 11:43:08 AM
If I hide and embed a .jpg inside a .docx file, exiftool v8.75 does not report on the .jpg.

Jack

Phil Harvey

#11
June 01, 2012, 01:25:48 PM
Correct.
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).
Print
Go Up Pages1
User actions