Abstract: Efficient encoding and/or decoding of digital video is provided using multiple candidate reference frames, making playback of the digital video optionally reversible. For example, a source can be encoded as duplex coded frames having multiple candidate reference frames. The reference frames can be previous or future frames, and the duplex coded frames can be encoded at a bit-rate that ensures lossless decoding using any of the candidate reference frames. Therefore, the duplex coded frames can encoded in normal and/or reverse temporal order. In this regard, the ability to decode digital video frames using either a single previous or future frame enables reversible digital video, bit-stream switching and video splicing arbitrary time points, and provides for increased error resilience.

Abstract: A method for encoding video includes receiving data, and encrypting the data using at least four Huffman trees. A method for encoding video includes receiving data, and encrypting the data such that an internal state of a stream cipher is independent of plaintext and ciphertext. A video encoding system for encoding video in a computing environment includes means for accessing data, and means for encrypting the data such that there are approximately 2106 possibilities.