mpeg1_frame_header
framelen[0] = mpeg1_frame_header(go, buf, 0, 1, PFRAME);
framelen[0] += mpeg1_frame_header(go, buf + framelen[0] / 8,
framelen[1] = mpeg1_frame_header(go, buf + i, 0, 1, BFRAME_PRE);
framelen[1] += mpeg1_frame_header(go, buf + i + framelen[1] / 8,
framelen[2] = mpeg1_frame_header(go, buf + i, 0, 1, BFRAME_POST);
framelen[2] += mpeg1_frame_header(go, buf + i + framelen[2] / 8,
framelen[3] = mpeg1_frame_header(go, buf + i, 0, 1, BFRAME_BIDIR);
framelen[3] += mpeg1_frame_header(go, buf + i + framelen[3] / 8,