Bit allocation in a coded video sequence

An apparatus for encoding video pictures of a sequence of video pictures, wherein each picture is defined by one picture type of a plurality of picture types and each picture has a complexity, the apparatus comprising:

• (a) means for providing a complexity estimate for each picture type, wherein encoding a picture at an average quantization level produces an encoded bitstream having a codesize related to the complexity of the picture;
• (b) means for determining an average quantization level for the first picture of each picture type in accordance with a target codesize and complexity estimate of each said first picture, respectively;
• (c) means for encoding the first picture of each picture type at its respective average quantization level;
• (d) means for determining an actual average quantization level at which each first picture was actually encoded by means (c);
• and
• (e) means for updating the complexity estimate for each picture type in accordance with the actual average quantization level and codesize of the first picture of the picture type encoded by means (c).

A computer-readable medium having stored thereon a plurality of instructions, wherein the plurality of instructions are for encoding video pictures of a sequence of video pictures, wherein each picture is defined by one picture type of a plurality of picture types and each picture has a complexity, and wherein the plurality of instructions, when executed by a processor of a computer system having a storage area, cause the processor to perform the steps of:

• (a) providing a complexity estimate for each picture type, wherein encoding a picture at an average quantization level produces an encoded bitstream having a codesize related to the complexity of the picture;
• (b) determining an average quantization level for the first picture of each picture type in accordance with a target codesize and complexity estimate of each said first picture, respectively;
• (c) encoding the first picture of each picture type at its respective average quantization level;
• (d) determining an actual average quantization level at which each first picture was actually encoded in step (c);
• and
• (e) updating the complexity estimate for each picture type in accordance with the actual average quantization level and codesize of the first picture of the picture type encoded in step (c).