Multimedia distribution system for multimedia files with packed frames

A method for decoding and playing back media content, the method comprising:

• receiving at least a portion of a multimedia file, where the multimedia file comprises:
• a sequence of encoded video frames contained within at least one chunk, where:
• a number of the encoded video frames are at least partially encrypted encoded video frames that include at least one block of encrypted bytes;
• and
• each chunk includes a subset of video frames from the sequence of encoded video frames;
• an index that includes information indicative of locations of each encoded video frame within the sequence of encoded video frames;
• a set of digital rights management (DRM) information, where DRM information corresponding to an encoded video frame that includes at least one block of encrypted bytes comprises:
• an offset value that indicates the start of a block of encrypted bytes within an encoded video frame and a number value that indicates a number of encrypted bytes in the block of encrypted bytes;
• and
• cryptographic information that can be used to decrypt the encrypted block indicated by the offset value and the number value;
• processing the index to identify location information for a particular encoded video frame, where the particular encoded video frame is a partially encrypted encoded video frame that includes at least one block of encrypted bytes;
• locating the particular encoded video frame within a specific chunk;
• identifying DRM information corresponding to the particular encoded video frame within the set of DRM information;
• decrypting at least one block of encrypted bytes within the particular encoded video frame using offset and number values, and cryptographic information from the identified DRM information corresponding to the particular encoded video frame, where the decryption of the particular encoded video frame occurs prior to commencing decoding the decrypted video frame;
• decoding the particular encoded video frame;
• and
• playing back video frames including the decoded video frame.

A method for decoding and playing back media content, the method comprising:

• receiving at least a portion of a multimedia file, where the multimedia file comprises:
• a sequence of encoded video frames contained within at least one chunk, where:
• a number of the encoded video frames are at least partially encrypted encoded video frames;
• and
• each chunk includes a subset of encoded video frames from the sequence of encoded video frames;
• an index that includes information indicative of the start of locations of encoded video frames within the multimedia file;
• and
• a set of digital rights management (DRM) information that identifies portions of the at least partially encrypted encoded video frames that are encrypted, wherein each DRM information for a particular encoded video frame comprises an offset value that indicates a start of a block of encrypted bytes as an offset relative to a start of the particular encoded video frame and a number value that indicates a number of encrypted bytes in the block of encrypted bytes;
• processing the index to identify location information for a particular encoded video frame, where the particular encoded video frame is a partially encrypted encoded video frame;
• locating the particular encoded video frame within a specific chunk;
• processing the DRM information to identify at least one portion of the particular encoded video frame that is encrypted;
• decrypting, prior to decoding the particular encoded video frame, the at least one portion of the particular encoded video frame identified as encrypted by the DRM information;
• decoding the particular encoded video frame including the decrypted at least one portion of the particular encoded video frame identified by the DRM information as being encrypted after the encrypted portion is decrypted;
• and
• playing back video frames including the decoded video frame.