diff --git a/libavdevice/caca.c b/libavdevice/caca.c
index dd20ba3636..0a7470120f 100644
--- a/libavdevice/caca.c
+++ b/libavdevice/caca.c
@@ -140,7 +140,7 @@ static int caca_write_header(AVFormatContext *s)
         goto fail;
     }
 
-    bpp = av_get_bits_per_pixel(av_pix_fmt_desc_get(avctx->pix_fmt));
+    bpp = av_get_bits_per_pixel(av_pix_fmt_desc_get(encctx->pix_fmt));
     c->dither = caca_create_dither(bpp, encctx->width, encctx->height,
                                    bpp / 8 * encctx->width,
                                    0x0000ff, 0x00ff00, 0xff0000, 0);