Encoding device and method and multimedia apparatus including the encoding device

A multimedia apparatus, comprising:

• an input unit configured to receive a signal to be encoded;
• an encoding device configured to perform encoding by quantizing the signal received at-the input unit according to a group-of-pictures (GOP)-based bit assignment, a macroblock-based bit assignment, and a buffer state;
• a transmitting unit configured to transmit a bitstream encoded by the encoding device;
• a storing unit configured to store the bitstream encoded by the encoding device;
• and
• a control unit configured to control the input unit, the encoding device, the transmitting unit, and the storing unit,
• wherein the encoding device includes (i) a group-of-pictures (GOP)-based bit assigning unit configured to assign a GOP-based bit amount targetGOP, and (ii) a macroblock-based bit assigning unit configured to assign a macroblock-based bit amount for all macroblocks included in the GOP;
• wherein the GOP-based bit assigning unit is configured to
• divide a target bit rate per second targetsec by a frame per second fps, and
• multiply a result of the division by a key frame interval Iinterval, thereby calculating the GOP-based bit amount targetGOP;
• and
• wherein the macroblock-based bit assigning unit is configured to determine whether the macroblock is a first macroblock in the GOP when encoding on the GOP starts, and
• when the macroblock is the first macroblock, the macroblock-based bit assigning unit assigns a bit amount to each intra macroblock and each inter macroblock, which are two modes of the macroblock.

An encoding method performed by an encoding device, the encoding method comprising:

• assigning a group-of-pictures (GOP)-based bit amount targetGOP;
• assigning a macroblock-based bit amount for all macroblocks included in the GOP according to a mode;
• checking a current buffer state;
• determining a quantization parameter (QP) by using an alternating current (AC) coefficient obtained by transforming a macroblock;
• performing quantization by using the determined QP when a buffer occupancy rate is lower than a predetermined limit rate;
• and
• performing variable length coding (VLC),
• wherein the assigning of the GOP-based bit amount targetGOP comprises
• dividing a target bit rate per second targetsec by a frame per second fps, and
• multiplying a result of the division by a key frame interval IInterval, thereby calculating the GOP-based bit amount targetGOP, and
• wherein the assigning of the macroblock-based bit amount comprises
• determining whether the macroblock is a first macroblock in the GOP when encoding on the GOP starts and an assigning operation of assigning a bit amount in units of a macroblock, and
• when the macroblock is the first macroblock in the determining operation, assigning a bit amount to each intra macroblock and each inter macroblock, which are two modes of the macroblock.