Patent ID: 7539393
Filing Date: 2009-05-26
Classification: H04N

Abstract:
1. A method comprising: receiving a request to play compressed multimedia data in a reverse direction; identifying compressed video data in the compressed multimedia data; identifying compressed audio packets associated with the compressed video data; identifying a most recent key frame previously received; identifying a most recent audio key packet previously received; decoding the most recent key frame; decoding the most recent audio key packet; identifying delta frames received subsequent to the most recent key frame; identifying audio delta packets received subsequent to the most recent audio key packet; decoding the identified delta frames; decoding the identified audio delta packets; reducing an amount of data associated with each pixel in each decoded delta frame by: deleting alternating rows of pixels in each decoded delta frame; and deleting alternating pixels in non-deleted rows of pixels in each decoded delta frame; storing the reduced amount of data associated with each decoded delta frame; discarding alternating audio delta packets; deleting N of P delta frames, wherein N and P are integers and wherein N is determined based on a combination of the amount of memory available for storing decoded video frames and the frame rate desired during reverse playback; and playing the remaining identified delta frames in the reverse direction and concurrently playing the remaining decoded audio packets in reverse order.