Streaming media video encryption method and device based on H.264

The embodiment of the invention discloses a streaming media video encryption method and device based on H.264. The encryption method includes the steps that context-based adaptive variable length coding and QTC encryption are synchronously performed on the QTC, and the processed QTC is obtained; the prediction mode and motion vectors are scrambled, and the scrambled prediction mode and the scrambled motion vectors are obtained; multiplexing is performed on the processed QTC, the scrambled prediction mode and the scrambled motion vectors, and encrypted video data streams are input. Through the encryption method and device, the intra-frame prediction mode scrambling method in the prior art is improved, and Friedman key guessing and known plaintext attach can be prevented; safety of motion content is enhanced; the method is easy to achieve, real-time application complexity of data encryption in real-time application can be reduced, and the code error robustness of transmission of encrypted code streams is improv