An encoder encodes pixels representative of a picture in a multimedia stream, generates a first approximate signature based on approximate values of pixels in a reconstructed copy of the picture, and transmits the encoded pixels and the first approximate signature. A decoder receives a first packet including the encoded pixels and the first approximate signature, decodes the encoded pixels, and transmits a first signal in response to comparing the first approximate signature and a second approximate signature generated based on approximate values of the decoded pixels. If a corrupted packet is detected, the multimedia application requests an intra-coded picture in response to the first approximate signature differing from the second approximate signature. The second signal instructs the decoder to bypass requesting an intra-coded picture and to continue decoding received packets in response to the first approximate signature being equal to the second approximate signature.