For two-way video communications over wireless channels using the automatic repeat request (ARQ) retransmission scheme, TMN8 rate control scheme is not effective in minimizing the number of frames skipped and cannot guarantee video quality during the retransmissions of error packets. This paper presents a joint source channel bit allocation scheme that allocates target bits according to encoder buffer fullness and estimation of channel condition by retransmission information. The results obtained from implementing our scheme in H. 263 + coder over wireless channel model show that our proposed scheme encodes the video sequences with lower and steadier buffer delay, fewer frames skipped and higher average PSNR compared to TMN8.