for (x = mb = 0; x < ctx->mb_width; x += mbs_per_slice, mb++) {
q = ctx->force_quant ? ctx->force_quant
: ctx->slice_q[mb + y * ctx->slices_width];
for (x = mb = 0; x < ctx->mb_width; x += mbs_per_slice, mb++) {
q = ctx->force_quant ? ctx->force_quant
: ctx->slice_q[mb + y * ctx->slices_width];