Add av_image_check_sar() and use it to validate SAR

1 files changed, 33 insertions, 0 deletions

diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index dff84197c9..33983f86fe 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -153,6 +153,21 @@ int ff_set_dimensions(AVCodecContext *s, int width, int height)
     return ret;
 }
 
+int ff_set_sar(AVCodecContext *avctx, AVRational sar)
+{
+    int ret = av_image_check_sar(avctx->width, avctx->height, sar);
+
+    if (ret < 0) {
+        av_log(avctx, AV_LOG_WARNING, "ignoring invalid SAR: %u/%u\n",
+               sar.num, sar.den);
+        avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
+        return ret;
+    } else {
+        avctx->sample_aspect_ratio = sar;
+    }
+    return 0;
+}
+
 int ff_side_data_update_matrix_encoding(AVFrame *frame,
                                         enum AVMatrixEncoding matrix_encoding)
 {
@@ -636,6 +651,14 @@ int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
         if (!frame->sample_aspect_ratio.num)
             frame->sample_aspect_ratio = avctx->sample_aspect_ratio;
 
+        if (av_image_check_sar(frame->width, frame->height,
+                               frame->sample_aspect_ratio) < 0) {
+            av_log(avctx, AV_LOG_WARNING, "ignoring invalid SAR: %u/%u\n",
+                   frame->sample_aspect_ratio.num,
+                   frame->sample_aspect_ratio.den);
+            frame->sample_aspect_ratio = (AVRational){ 0, 1 };
+        }
+
         if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)
             return ret;
         break;
@@ -1071,6 +1094,16 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code
         ff_set_dimensions(avctx, 0, 0);
     }
 
+    if (avctx->width > 0 && avctx->height > 0) {
+        if (av_image_check_sar(avctx->width, avctx->height,
+                               avctx->sample_aspect_ratio) < 0) {
+            av_log(avctx, AV_LOG_WARNING, "ignoring invalid SAR: %u/%u\n",
+                   avctx->sample_aspect_ratio.num,
+                   avctx->sample_aspect_ratio.den);
+            avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
+        }
+    }
+
     /* if the decoder init function was already called previously,
      * free the already allocated subtitle_header before overwriting it */
     if (av_codec_is_decoder(codec))