added the export driver interface: IExporter

diff --git a/export/api.py b/export/api.py
new file mode 100644 (file)
index 0000000..6156581
--- /dev/null
+++ b/export/api.py
@@ -0,0 +1,56 @@
+
+class IExporter():
+    """Export driver interface"""
+
+    # Remark: the method prototypes do not include any self or cls argument 
+    # because an interface is meant to show what methods a class must expose 
+    # from the caller's point of view. However, when implementing the class 
+    # you'll obviously want to include this extra argument.
+
+    def get_format():
+        """Return the export/encoding format as a short string 
+        Example: "MP3", "OGG", "AVI", ...
+        """
+   
+    def get_description():
+        """Return a string describing what this export format provides, is good 
+        for, etc... The description is meant to help the end user decide what 
+        format is good for him/her
+        """
+
+    def get_file_extension():
+        """Return the filename extension corresponding to this export format"""
+
+    def get_mime_type():
+        """Return the mime type corresponding to this export format"""
+
+    def set_cache_directory(path):
+        """Set the directory where cached files should be stored. Does nothing
+        if the exporter doesn't support caching. 
+       
+        The driver shouldn't assume that this method will always get called. A
+        temporary directory should be used if that's not the case.
+        """
+
+    def process(item_id, source, metadata)
+        """Perform the exporting process and return the absolute path 
+        to the resulting file.
+
+        item_id is the media item id that uniquely identifies this audio/video
+        resource
+
+        source is the audio/video source file absolute path. For audio that should
+        be a WAV file
+
+        metadata is a dictionary
+
+        The returned file path is not meant to be permanent in any way, it 
+        should be considered temporary/volatile by the caller.
+
+        It is highly recommended that export drivers implement some sort of cache
+        instead of re-encoding each time process() is called. 
+
+        It should be possible to make subsequent calls to process() with different
+        items, using the same driver instance.
+        """
+