I would like to get the Chapter length out of the id3 tags from a .m4a podcast file. I am using the PHP framework getID3() to analysis the file.
In the data I found an array with the amount of chapters and an attribute which calls "sample_duration" with an example value of around 50000. Now is my question how i can get the length in minutes, or do I get the length of chapters through offset attributes in the tags.
When I add all the sample_duration values i get 1988440, But in what unity is this measured?
The length of the whole file is 55 minutes and 14 seconds.
To visualize the data you could use http://jsonviewer.stack.hu/.
After some deeper analysis of the data, I found the "time_scale" attribute, with which I can calculate the chapter durations in seconds.