Distributed video coding apparatus and method capable of controlling encoding rate

A distributed video coding apparatus capable of controlling an encoding rate, the apparatus comprising:

• an intra-frame encoder configured to encode a key frame and output a bit stream of the encoded key frame;
• an encoder rate control (ERC) module configured to calculate a bit rate according to motion complexity of a present Wyner-Ziv (WZ) frame by using a correlation between the motion complexity and the bit rate;
• and
• a turbo encoder configured to encode the present WZ frame by the bit rate calculated at the ERC module and output a WZ bit stream,
• wherein the motion complexity of the present WZ frame is calculated as follows:
• β
• 2
• ⁢
• i
• =
• 1
• m
• ×
• n
• ⁢
• (
• ∑
• k
• =
• 1
• m
• ⁢
• ⁢
• ∑
• l
• =
• 1
• n
• ⁢
• ⁢
• 
• I
• 2
• ⁢
• i
• -
• 1
• ⁡
• (
• k
• ,
• l
• )
• -
• X
• 2
• ⁢
• i
• ⁡
• (
• k
• ,
• l
• )
• 
• )
• wherein β2i indicates the motion complexity of the present WZ frame X2i, m×n indicates a size of an image, I2i−1 indicates a previous key frame, X2i indicates the present WZ frame, and (k, 1) indicates pixel coordinates.