coda_parabuf_write
coda_parabuf_write(ctx, i * 3 + 0, y);
coda_parabuf_write(ctx, i * 3 + 1, cb);
coda_parabuf_write(ctx, i * 3 + 2, cr);
coda_parabuf_write(ctx, 96 + i, mvcol);
coda_parabuf_write(ctx, 97, mvcol);