System and method for video encoding

An encoding device comprising:

• a compression unit;
• a quantizer coupled to the output of said compression unit;
• an iterative bit estimator coupled to the output of said quantizer without any intervening elements that affect an encoded bits stream;
• a bit rate encoder configured to receive the output of said bit estimator and the output of said encoder coupled to the control input of said quantizer;
• a variable length encoder coupled to the output of said quantizer;
• and
• to provide the final encoded bits stream;
• wherein said bit estimator includes:
• a current frame macroblock bit estimator;
• a previous frames bit estimator configured to generate a bit estimation, such that the bit estimation is based on at least two sets of groupings of data in the bit stream corresponding to at least two previous bit estimations and each grouping having a weight attached to non-zero AC coefficients different from any other grouping weighting such that each grouping weighting is greater than any previous grouping weighting;
• and
• a linear estimator coupled to said current frame macroblock bit estimator and said previous frames bit estimator.

A method of encoding comprising:

• compressing a sampled data stream comprising a plurality of macroblocks;
• quantizing said compressed data stream;
• obtaining a number of bits required to encode the macroblock in a current frame:
• obtaining a number of bits required to encode at least two previous frames:
• performing a linear function of said obtained numbers to estimate the exact number of bits required to encode the macroblock in the current frame such that the linear function includes weightings, attached to non-zero AC coefficients, of descending value corresponding to previous frames, respectively;
• iteratively estimating the number of bits based upon the compressed data stream received directly after quantizing to encode a macroblock of the compressed data;
• adapting said quantization based on the estimated number of bits after each estimation;
• performing variable length encoding of the quantized data and providing the final encoded bits stream.

An encoder, comprising;

• an estimator configured to iteratively estimate a number of bits for encoding a first portion of a stream of compressed data based on at least two sets of groupings, each grouping having a weight attached to non-zero AC coefficients different from any other grouping weighting such that each grouping weighting is greater than any previous grouping weighting and a number of compression coefficients in a second portion of the stream having a characteristic;
• a generator configured to generate a quantization parameter in response to the estimated number of bits after each iteration;
• and
• a quantizer configured to quantize the compressed data in response to the quantization parameter;
• wherein the estimator estimates the bits based at least on the compressed data directly from the quantizer.

A system, comprising:

• a first integrated circuit comprising
• an image data generator configured to generate a stream of image data;
• and
• an image data encoder, comprising:
• a data compressor configured to generate a stream of compressed data;
• a quantizer configured to quantize the stream of compressed data in response to a quantization parameter;
• an estimator configured to iteratively estimate a number of bits for encoding a first portion of the stream of quantized compressed data based on at least two sets of differently weighted groupings, each grouping having a weight attached to non-zero AC coefficients different from any other grouping weighting such that each grouping weighting is greater than any previous grouping weighting and a number of compression coefficients in a second portion of the stream of quantized compressed data having a characteristic such that the estimator estimates the bits based at least on the compressed data directly from the quantizer;
• and
• a generator configured to generate the quantization parameter in response to the estimated number of bits after each iteration;
• and
• a second integrated circuit coupled to the first integrated circuit.

A method, comprising:

• iteratively estimating a number of bits for encoding a first portion of a stream of compressed data based on at least two sets of differently weighted groupings, each grouping having a weight attached to non-zero AC coefficients different from any other grouping weighting such that each grouping weighting is greater than any previous grouping weighting and a number of compression coefficients in a second portion of the stream having a characteristic;
• generating a quantization parameter in response to the estimated number of bits after each iteration;
• and
• quantizing the compressed data in response to the quantization parameter;
• wherein the estimating is based on the compressed data directly after quantizing.

A method, comprising:

• generating a stream of compressed data;
• quantizing the stream of compressed data in response to a quantization parameter;
• iteratively estimating a number of bits for encoding a first portion of the stream of quantized compressed data directly after quantizing based on at least two sets of differently weighted groupings, each grouping having a weight attached to non-zero AC coefficients different from any other grouping weighting such that each grouping weighting is greater than any previous grouping weighting and a number of compression coefficients in a second portion of the stream of quantized compressed data having a characteristic;
• and
• generating the quantization parameter in response to the estimated number of bits after each iteration.