README.md in file_data-5.0.0 vs README.md in file_data-5.2.0
- old
+ new
@@ -2,17 +2,32 @@
=========
[](https://travis-ci.org/ScottHaney/file_data)
[](https://coveralls.io/github/ScottHaney/file_data?branch=master)
[](https://codeclimate.com/github/ScottHaney/file_data)
+[](https://badge.fury.io/rb/file_data)
Ruby library that reads file metadata.
-Current support
+The api provides a basic usage and an advanced usage. The basic usage will reopen and reparse the file every time it is called which is no problem when reading a single value but can be a performance drain for multiple values. The advanced usage allows the user to grab more than one value without having to read the file more than once.
-* Exif: Only jpeg files are supported and FlashPix extensions are not supported
+## Basic Usage
+```ruby
+filepath = '...' # Path to a jpeg or mpeg4 file
+
+# Get the date when the file content originated. When a photo was taken, when a movie was recorded, etc
+FileData::FileInfo.origin_date(filepath)
+
+# Get the date when the file was considered to be created. This is usually tied in some way to when the file itself was created on a disk somewhere (not usually as useful as origin date)
+FileData::FileInfo.creation_date(filepath)
+```
+
+## Advanced Usage
+
+Varies by file format type. Currently there are low level classes for parsing exif and mpeg4 metadata
+
## Exif documentation
Exif data is hierarchical and consists of tag/value pairs. The first level is whether or not the tag applies to the image or the image's thumbnail. Next a tag may be one of several sections and within the section it will have a unique numeric value. So given this terminology a unique key for an exif tag would be something like image/section1/123 for a tag that applies to the image in section 1 with a tag id of 123.
To read exif data a stream of the jpeg data should be used as input. For performance reasons all of the data that is desired should be extracted in a single method from FileData::Exif. All methods will manipulate the stream position after they are called and the user should not count on the stream position being at a specific location after a FileData::Exif method call.
@@ -219,6 +234,19 @@
{
1 => :Interoperability_Index
}
```
+## Mpeg4 documentation
+```ruby
+
+filepath = '...' # path to an mpeg4 file
+File.open(filepath, 'rb') do |stream|
+ parser = FileData::MvhdBoxParser # class that parses the box you want
+ method = :creation_time # attribute to get from the parse result
+ box_path = ['moov', 'mvhd'] # path to get to the box that you want
+
+ # final result that you are looking for
+ result = FileData::Mpeg4.get_value(stream, parser, method, *box_path)
+end
+```