Patent ID: 8995522
Filing Date: 2015-03-31
Classification: H04N

Abstract:
1. A method of coding a picture within a video stream with a limited number of coding passes, comprising: on each pass, coding the picture as a plurality of slices and macroblocks, image data of the macroblocks being subject to coefficient transforms and to quantization by a quantization parameter, wherein on a first pass, establishing the quantization parameter as a first value used for coding every slice of the picture, on a second pass, which is reached if a size of a coded picture data obtained from the first pass exceeds a predetermined limit, revising the quantization parameter to a second value and coding every slice of the picture using the second value, on a third pass, which is reached if a size of a code slice data obtained from the second pass exceeds a predetermined slice limit, revising the quantization parameter for each slice that exceeds an associated maximum slice size, on a slice-by-slice basis, and when a pass generates coded picture data that satisfies the predetermined limit, outputting the coded picture data to a channel.