Apparatus for constant quality rate control in video compression and target bit allocator thereof

• Main Authors: CHANG, YUNGING, CHEN, CHIAIEH, WANG, TENG-KAI
• Format: Patent
• Language: English
• Published: 11.01.2005
• Edition: 7
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

An apparatus for constant quality rate control in moving picture compression. First, a total activity measure for the current picture to be encoded in a set of consecutive pictures is calculated. Based on the total activity measure of the current picture and an activity-to-complexity ratio of a previously encoded picture of the same type in the set of consecutive pictures, a complexity measure of the current picture is estimated. Thus, an instantaneous complexity measure is updated using the complexity measure and then an instantaneous rate is calculated. A target bit budget is allocated to the current picture depending on the instantaneous rate, the complexity measure and the instantaneous complexity measure. After encoding, the activity-to-complexity ratio for the just encoded picture is computed based on the total activity measure, actual bits consumed by the picture and the average of actual quantization step sizes used to encode the picture.