Difference between revisions of "Truxton exif get thumbnail length"
Jump to navigation
Jump to search
(Created page with "This API retrieves the offset into the parent file where the thumbnail image length value began. =Syntax= <source lang="C"> uint64_t truxton_exif_get_thumbnail_length_offset(...") |
(→Sample) |
||
| (One intermediate revision by the same user not shown) | |||
| Line 1: | Line 1: | ||
| − | This API retrieves the | + | This API retrieves the number of bytes in the thumbnail image. |
=Syntax= | =Syntax= | ||
<source lang="C"> | <source lang="C"> | ||
| − | uint64_t | + | uint64_t truxton_exif_get_thumbnail_length( uint64_t exif_handle ); |
</source> | </source> | ||
| Line 11: | Line 11: | ||
=Return value= | =Return value= | ||
| − | The | + | The number of bytes in the thumbnail image. |
=Sample= | =Sample= | ||
| Line 97: | Line 97: | ||
printf( "Thumbnail Offset offset: %" PRIu64 "\n", integer_value ); | printf( "Thumbnail Offset offset: %" PRIu64 "\n", integer_value ); | ||
| − | integer_value = | + | integer_value = truxton_exif_get_thumbnail_length( exif_handle ); |
| − | printf( "Thumbnail Length | + | printf( "Thumbnail Image Length: %" PRIu64 "\n", integer_value ); |
integer_value = truxton_exif_get_make_offset( exif_handle ); | integer_value = truxton_exif_get_make_offset( exif_handle ); | ||
| Line 113: | Line 113: | ||
} | } | ||
</source> | </source> | ||
| + | |||
| + | The <code>PRIu64</code> in the sample code above is a standard way of [https://en.wikipedia.org/wiki/C_data_types#Printf_and_scanf_format_specifiers formatting] a 64-bit unsigned integer in C. | ||
| + | Over the years, different compilers on different operating systems used different format specifiers for things, these <code>PRI</code> macros, along with some tricky string concatenation the compilers perform for you, allow you to maintain a single code base without a bunch of macro magic. | ||
Latest revision as of 07:07, 6 February 2021
This API retrieves the number of bytes in the thumbnail image.
Syntax
uint64_t truxton_exif_get_thumbnail_length( uint64_t exif_handle );
Parameters
exif_handle
This handle comes from calling truxton_exif_create() or truxton_file_create_exif().
Return value
The number of bytes in the thumbnail image.
Sample
void dump_exif( uint64_t exif_handle )
{
double floating_point_value = 0.0;
uint64_t integer_value = 0;
char id[ 65 ];
truxton_exif_get_id( exif_handle, id, sizeof( id ) );
printf( "ID: %s\n", id );
truxton_exif_get_file_id( exif_handle, id, sizeof( id ) );
printf( "File ID: %s\n", id );
truxton_exif_get_media_id( exif_handle, id, sizeof( id ) );
printf( "Media ID: %s\n", id );
truxton_exif_get_make( exif_handle, id, sizeof( id ) );
printf( "Make: %s\n", id );
truxton_exif_get_model( exif_handle, id, sizeof( id ) );
printf( "Model: %s\n", id );
truxton_exif_get_body_serial_number( exif_handle, id, sizeof( id ) );
printf( "Body serial number: %s\n", id );
truxton_exif_get_lens_serial_number( exif_handle, id, sizeof( id ) );
printf( "Lens serial number: %s\n", id );
integer_value = truxton_exif_get_device_time( exif_handle );
printf( "Device Time: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_gps_time( exif_handle );
printf( "GPS Time: %" PRIu64 "\n", integer_value );
floating_point_value = truxton_exif_get_focal_length( exif_handle );
printf( "35mm Focal Length: %lf\n", floating_point_value );
floating_point_value = truxton_exif_get_heading( exif_handle );
printf( "Heading: %lf degrees\n", floating_point_value );
floating_point_value = truxton_exif_get_latitude( exif_handle );
printf( "Latitude: %lf degrees\n", floating_point_value );
floating_point_value = truxton_exif_get_longitude( exif_handle );
printf( "Longitude: %lf degrees\n", floating_point_value );
floating_point_value = truxton_exif_get_altitude( exif_handle );
printf( "Altitude: %lf meters\n", floating_point_value );
integer_value = truxton_exif_get_shutter_count( exif_handle );
printf( "Shutter Count: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_offset( exif_handle );
printf( "EXIF Data Block found at offset %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_gps_time_offset( exif_handle );
printf( "GPS Time offset: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_device_time_offset( exif_handle );
printf( "Device Time offset: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_latitude_offset( exif_handle );
printf( "Latitude offset: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_longitude_offset( exif_handle );
printf( "Longitude offset: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_altitude_offset( exif_handle );
printf( "Altitude offset: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_heading_offset( exif_handle );
printf( "Heading offset: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_focal_length_offset( exif_handle );
printf( "Focal Length offset: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_shutter_count_offset( exif_handle );
printf( "Shutter Count offset: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_thumbnail_offset_offset( exif_handle );
printf( "Thumbnail Offset offset: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_thumbnail_length( exif_handle );
printf( "Thumbnail Image Length: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_make_offset( exif_handle );
printf( "Make offset: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_model_offset( exif_handle );
printf( "Model offset: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_body_serial_number_offset( exif_handle );
printf( "Body Serial Number offset: %" PRIu64 "\n", integer_value );
integer_value = truxton_exif_get_lens_serial_number_offset( exif_handle );
printf( "Lens Serial Number offset: %" PRIu64 "\n", integer_value );
}
The PRIu64 in the sample code above is a standard way of formatting a 64-bit unsigned integer in C.
Over the years, different compilers on different operating systems used different format specifiers for things, these PRI macros, along with some tricky string concatenation the compilers perform for you, allow you to maintain a single code base without a bunch of macro magic.
