imgconvert-test: add avg bits per pixel

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/imgconvert.c

@@ -982,7 +982,7 @@ int main(void){
         AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(i);
         if(!desc)
             continue;
-        av_log(0, AV_LOG_INFO, "pix fmt %s %d\n", desc->name, is_yuv_planar(i));
+        av_log(0, AV_LOG_INFO, "pix fmt %s yuv_plan:%d avg_bpp:%d\n", desc->name, is_yuv_planar(i), avg_bits_per_pixel(i));
     }
     return 0;
 }