In this paper, a frame-level joint rate control scheme for both intra-and inter-predictive coding is first introduced for a hybrid video codec system that independently encodes the two-view sequences of a stereoscopic video. The proposed rate control scheme jointly works on the left view encoder of MPEG-2 Video and the right view encoder of an H.264/AVC for stereoscopic video input, and is formulated as optimization problems that allow control of the output bit rates of both encoders in the sense that: 1) the sum of the two decoded video qualities is maximized, and 2) the quality difference is maintained around a desired level for a given target bit budget at the same time. In order to verify the effectiveness of the proposed joint rate scheme, it is compared with an independent rate control scheme. The experimental results show that the joint rate control scheme effectively regulates the output bitstreams of the hybrid encoders based on MPEG-2 Video and H.264/AVC. The joint rate control scheme achieves average 0.71 dB gain in PSNR and 67.07% reduction in the MSE of PSNR difference for I-frame only, average 0.54 dB gain and 91.08% reduction for IPPP coding, and average 0.32 dB gain and 79.01% reduction for IBBP coding.