An electronic device with one or more processors, memory and a display obtains a file header for a file that corresponds to a plurality of separately indexed clusters. The file is divided into segments one or more of which include multiple sequential clusters. The file header includes a segment index that enables identification of a segment that includes requested content. The device receives a request to seek to a respective position within the file. In response, the device identifies a first segment that includes content that corresponds to the respective position based on the segment index, obtains the first segment, and obtains a content index for a respective cluster within the first segment. After obtaining the first segment and the content index, the device identifies respective content within the respective cluster that corresponds to the respective position based on a content index and provides the respective content to a user.