Question about video metadata handling

[Michael G. Hansen]

Hi,

two questions about video metadata handling:

Current schema of VideoMetadata:
CREATE TABLE VideoMetadata
                             (imageid INTEGER PRIMARY KEY,
                             aspectRatio TEXT,
                             audioBitRate TEXT,
                             audioChannelType TEXT,
                             audioCompressor TEXT,
                             duration TEXT,
                             frameRate TEXT,
                             exposureProgram INTEGER,
                             videoCodec TEXT);

1. Video metadata is stored as text in the database, even things like
audioBitRate, duration and frameRate. Is this intentional? Can we change
it to REAL to avoid string-to-real conversions needed for locale-aware
display of the data and for sorting?

2. The aspect ratio of videos is also stored in the database, although
the width and height are also available, which means that the aspect
ratio could simply be calculated. This information is also displayed
twice in digikam, once for image properties and once for video
properties. Is there a special reason to store the aspect ratio like
this or can we remove it?

Best regards,

Michael
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[Abhinav Badola]

Hi Michael,

On Sun, May 26, 2013 at 5:34 PM, Michael G. Hansen <[hidden email]> wrote:

Hi,

two questions about video metadata handling:

Current schema of VideoMetadata:
CREATE TABLE VideoMetadata
                            (imageid INTEGER PRIMARY KEY,
                            aspectRatio TEXT,
                            audioBitRate TEXT,
                            audioChannelType TEXT,
                            audioCompressor TEXT,
                            duration TEXT,
                            frameRate TEXT,
                            exposureProgram INTEGER,
                            videoCodec TEXT);

1. Video metadata is stored as text in the database, even things like audioBitRate, duration and frameRate. Is this intentional? Can we change it to REAL to avoid string-to-real conversions needed for locale-aware display of the data and for sorting?

When I created the database it was primarily for the task of displaying information.
Sure you should change it to REAL or INTEGER, if that is how it would work best.
 

2. The aspect ratio of videos is also stored in the database, although the width and height are also available, which means that the aspect ratio could simply be calculated. This information is also displayed twice in digikam, once for image properties and once for video properties. Is there a special reason to store the aspect ratio like this or can we remove it?

I think it should be removed. It can be computed from width and height. I added this as we were picking up the data directly from Exiv2 xmp metadata. Previously it was not being computed within digiKam.
I think it should be removed from Video Properties, but maintained in the Image Properties.

Best regards,

Michael
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--
Regards,
Abhinav Badola

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[Marcel Wiesweg]

> two questions about video metadata handling:
>
> Current schema of VideoMetadata:
> CREATE TABLE VideoMetadata
>                              (imageid INTEGER PRIMARY KEY,
>                              aspectRatio TEXT,
>                              audioBitRate TEXT,
>                              audioChannelType TEXT,
>                              audioCompressor TEXT,
>                              duration TEXT,
>                              frameRate TEXT,
>                              exposureProgram INTEGER,
>                              videoCodec TEXT);
>
> 1. Video metadata is stored as text in the database, even things like
> audioBitRate, duration and frameRate. Is this intentional? Can we change
> it to REAL to avoid string-to-real conversions needed for locale-aware
> display of the data and for sorting?
>
> 2. The aspect ratio of videos is also stored in the database, although
> the width and height are also available, which means that the aspect
> ratio could simply be calculated. This information is also displayed
> twice in digikam, once for image properties and once for video
> properties. Is there a special reason to store the aspect ratio like
> this or can we remove it?

This was produced during GSoC. I did not really check the necessity and choice
of the fields, I relied on the student.
I am sure you have valid points here; the problem is any schema change would
drop compatibility, which means we should only do it in the future together
with a schema update necessary for other reasons.
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