|
(11) | EP 1 599 047 A8 |
(12) | CORRECTED EUROPEAN PATENT APPLICATION |
Note: Bibliography reflects the latest situation |
|
|
|
|
|||||||||||||||||||||||||||
|
(54) | Video (de)coding device with frequency band retransmission |
(57) A video-coding device and a video-decoding device, which are capable of assuring
the necessary quality of a video sequence even if a transmission error and/or a loss
of information occurs in a transmission line and preventing the propagation of decoding
error to subsequent images, and can effectively retransmit the necessary coded information
when a transmission error and/or a loss of information occurs in a transmission line.
A motion-compensated interframe-predicting portion (301) predicts an input image by
using a preceding decoded image stored in a frame memory portion (302) and outputs
motion vectors. A difference calculating portion (303) determines a difference between
the input image signal and the predicted image signal and outputs the difference as
a prediction-error signal to a band-dividing portion (304) which in turn divides the
prediction-error signal into n hierarchical layers of frequency-band-components and
outputs them to respective coding portions (305a to 305n). A loop-back control portion
(307) decides whether each of the coded frequency-band-components of the coded prediction-error
signal from respective coding portions is input to a synthesizing portion (309) and
outputs a decoded prediction-error signal. The predicted image signal and the decoded
prediction-error signal are combined to generate a decoded image signal corresponding
to the input image. The decoded image signal is used for prediction of a subsequent
input image. A motion-compensated interframe-predicting portion (901) predicts an
input image by using a preceding decoded image stored in a frame memory portion (902)
and outputs motion vectors. A difference calculating portion (903) determines a difference
between the input image signal and the predicted image signal and outputs the difference
as a prediction-error signal to a band-dividing portion (904) which in turn divides
the prediction-error signal into n hierarchical layers of frequency-band-components
and outputs them to respective coding portions (905a to 905n) for quantizing and encoding
the respective components. Buffer portions (906a to 906n) store the coded information
and output the information to an external circuit. The buffers output respective frequency-band-components
of the coded information according to retransmission request signals from a retransmission
control portion (910).
|