TRANSCODER-BASED ADAPTIVE QUANTIZATION FOR DIGITAL VIDEO RECORDING

摘要

The present invention provides a transcoding architecture and a consumer set-top box with storage capability that is based on the transcoding architecture and capable of operating efficiently in an all-digital environment. In a preferred embodiment, a digital-VIDEO DEVICE employs an MPEG-2 compliant transcoder that includes a simplified cascaded decoder and encoder, and is capable of performing determinable bitrate re-encoding without conducting motion estimation. During recording, the decoder receives and processes a compressed source bitstream, producing a decoded bitstream that includes reconstructed video and preserved motion vectors. The encoder "re-encodes" the decoded bitstream using the preserved motion vectors and performs any applicable bitrate modifications. The re-encoded bitstream is then stored.