Methods And Apparatus For Improving Backward Seek Performance For Multimedia Files

A portable electronic device, comprising:

• one or more processors;
• memory coupled to the one or more processors;
• an audio/video output device coupled to the one or more processors;
• the memory for storing one or more multimedia files;
• a file system which is executable by the one or more processors, the file system being adapted to manage storage of the multimedia files in the memory;
• a multimedia player application which is executable by the one or more processors, the multimedia player application being adapted to process multimedia data of the multimedia files to produce multimedia output data at the audio/video output device;
• an interface process which is executable by the one or more processors for interfacing between the multimedia player module and the file system, the interface process being adapted to:
• maintain a current address pointer which corresponds to a current position in the multimedia file being played by the multimedia player application;
• maintain a backward seek address pointer which corresponds to a preceding position in the multimedia file between the current position and the beginning of the multimedia tile;
• for each one of a plurality of multimedia data requests for multimedia data from the multimedia player application:
• receive, from the multimedia player application, a multimedia data request for multimedia data which includes a requested offset value to the requested multimedia data in the multimedia file;
• if the requested offset value corresponds to a position in the multimedia file that follows the current position associated with the current address pointer:
• submit, to the file system, a corresponding data request for the requested multimedia data which includes the current address pointer and an offset value;
• and
• if the requested offset value corresponds to a position in the multimedia file that precedes the current position associated with the current address pointer:
• submit, to the file system, a corresponding data request for the requested multimedia data which includes the backward seek address pointer and an offset value.

An interface module for use in processing multimedia data requests for multimedia data in a multimedia file which is managed by a file system, the interface module being adapted to maintain a current address pointer which corresponds to a current position in the multimedia tile;

• maintain a backward seek address pointer which corresponds to a preceding position in the multimedia file between the current position and the beginning of the multimedia file;
• receive, from a multimedia player module, a multimedia data request for multimedia data which includes a requested offset value to the requested multimedia data in the multimedia file;
• if the requested offset value corresponds to a position in the multimedia file that follows the current position associated with the current address pointer:
• submit, to the file system, a corresponding data request for the requested multimedia data which includes the current address pointer and an offset value;
• if the requested offset value corresponds to a position in the multimedia file that precedes the current position associated with the current address pointer:
• submit, to the file system, a corresponding data request for the requested multimedia data which includes the backward seek address pointer and an offset value;
• and submit the requested multimedia data to the multimedia player module in response to the multimedia data request.