A two-pass encoder determines a quantization parameter (QP) value to control an actual number of bits consumed in a second encoding pass. The two-pass encoder includes a first encoding module, a rate control module and a second encoding module. The first encoding module includes a circuit configured to perform a first encoding pass to encode input video sequences. The rate control module is configured to determine R, a target bit rate for a picture in the second encoding pass, and α, a variable dependent on a QP value range, a picture type, and complexity. Q, a QP value for the picture or an MB of the picture in the second encoding pass, is also determined based on R and α. The second encoding module is configured to use Q to encode the picture or the MB of the picture in the input video sequence in the second encoding pass to form an output bitstream. The rate control module is further configured to update α to encode a next picture or a next MB of the picture in the second encoding pass.