Add av_image_check_sar() and use it to validate SAR

1 files changed, 23 insertions, 0 deletions

diff --git a/libavutil/imgutils.c b/libavutil/imgutils.c
index 813724bea7..fc367d921b 100644
--- a/libavutil/imgutils.c
+++ b/libavutil/imgutils.c
@@ -25,7 +25,9 @@
 #include "imgutils.h"
 #include "internal.h"
 #include "log.h"
+#include "mathematics.h"
 #include "pixdesc.h"
+#include "rational.h"
 
 void av_image_fill_max_pixsteps(int max_pixsteps[4], int max_pixstep_comps[4],
                                 const AVPixFmtDescriptor *pixdesc)
@@ -228,6 +230,27 @@ int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *lo
     return AVERROR(EINVAL);
 }
 
+int av_image_check_sar(unsigned int w, unsigned int h, AVRational sar)
+{
+    int64_t scaled_dim;
+
+    if (!sar.den)
+        return AVERROR(EINVAL);
+
+    if (!sar.num || sar.num == sar.den)
+        return 0;
+
+    if (sar.num < sar.den)
+        scaled_dim = av_rescale_rnd(w, sar.num, sar.den, AV_ROUND_ZERO);
+    else
+        scaled_dim = av_rescale_rnd(h, sar.den, sar.num, AV_ROUND_ZERO);
+
+    if (scaled_dim > 0)
+        return 0;
+
+    return AVERROR(EINVAL);
+}
+
 void av_image_copy_plane(uint8_t       *dst, int dst_linesize,
                          const uint8_t *src, int src_linesize,
                          int bytewidth, int height)