Multimedia distribution system for multimedia files with interleaved media chunks of varying types

A system for decoding multimedia files comprising:

• at least one processor;
• a non-volatile storage containing a decoder application;
• wherein the decoder application causes the at least one processor to perform the steps of:
• receiving at least a portion of a multimedia file, wherein:
• the received at least a portion of the multimedia file comprises at least one video track encoded as a plurality of video chunks, a set of digital rights management (DRM) chunks, and an index chunk;
• at least one video chunk of the plurality of video chunks contains at least one partially encrypted frame of video so that only a portion of the encoded frame is encrypted;
• each DRM chunk of the set of DRM chunks comprises DRM information to decrypt at least one partially encrypted frame of video in at least one video chunk of the plurality of video chunks;
• the DRM information comprises an offset value that points to the start of an encrypted block within an encoded frame and a number value that indicates the number of encrypted bytes in the encrypted block;
• the index chunk includes information concerning the location of data chunks within the multimedia file including the locations of video chunks from the at least one video track;
• and
• for each chunk of the plurality of video chunks:
• determining whether the video chunk contains at least one partially encrypted frame of video;
• when a video chunk contains a partially encrypted frame of video, identifying a corresponding one of the set of DRM chunks that contains the DRM information for the partially encrypted frame of video, demultiplexing the partially encrypted frame from the video chunk, and decrypting the partially encrypted frame of video using the offset and number values from the DRM information for the partially encrypted frame of video;
• and
• decoding at least one encoded frame of video for display.