Merge pull request #5553 from pletessier:aspect-ratio

modules/videoio/include/opencv2/videoio/videoio_c.h

@@ -190,6 +190,8 @@ enum
     CV_CAP_PROP_SETTINGS      =37,
     CV_CAP_PROP_BUFFERSIZE    =38,
     CV_CAP_PROP_AUTOFOCUS     =39,
+    CV_CAP_PROP_SAR_NUM       =40,
+    CV_CAP_PROP_SAR_DEN       =41,
 
     CV_CAP_PROP_AUTOGRAB      =1024, // property for videoio class CvCapture_Android only
     CV_CAP_PROP_SUPPORTED_PREVIEW_SIZES_STRING=1025, // readonly, tricky property, returns cpnst char* indeed

modules/videoio/src/cap_ffmpeg_api.hpp

@@ -23,7 +23,9 @@ enum
     CV_FFMPEG_CAP_PROP_FRAME_HEIGHT=4,
     CV_FFMPEG_CAP_PROP_FPS=5,
     CV_FFMPEG_CAP_PROP_FOURCC=6,
-    CV_FFMPEG_CAP_PROP_FRAME_COUNT=7
+    CV_FFMPEG_CAP_PROP_FRAME_COUNT=7,
+    CV_FFMPEG_CAP_PROP_SAR_NUM=40,
+    CV_FFMPEG_CAP_PROP_SAR_DEN=41
 };
 
 

modules/videoio/src/cap_ffmpeg_impl.hpp

@@ -250,6 +250,7 @@ struct CvCapture_FFMPEG
     double  get_duration_sec() const;
     double  get_fps() const;
     int     get_bitrate() const;
+    AVRational get_sample_aspect_ratio(AVStream *stream) const;
 
     double  r2d(AVRational r) const;
     int64_t dts_to_frame_number(int64_t dts);
@@ -836,6 +837,10 @@ double CvCapture_FFMPEG::getProperty( int property_id ) const
 #else
         return (double)video_st->codec.codec_tag;
 #endif
+    case CV_FFMPEG_CAP_PROP_SAR_NUM:
+        return get_sample_aspect_ratio(ic->streams[video_stream]).num;
+    case CV_FFMPEG_CAP_PROP_SAR_DEN:
+        return get_sample_aspect_ratio(ic->streams[video_stream]).den;
     default:
         break;
     }
@@ -910,6 +915,28 @@ int64_t CvCapture_FFMPEG::dts_to_frame_number(int64_t dts)
     return (int64_t)(get_fps() * sec + 0.5);
 }
 
+AVRational CvCapture_FFMPEG::get_sample_aspect_ratio(AVStream *stream) const
+{
+    AVRational undef = {0, 1};
+    AVRational stream_sample_aspect_ratio = stream ? stream->sample_aspect_ratio : undef;
+    AVRational frame_sample_aspect_ratio  = stream && stream->codec ? stream->codec->sample_aspect_ratio : undef;
+
+    av_reduce(&stream_sample_aspect_ratio.num, &stream_sample_aspect_ratio.den,
+        stream_sample_aspect_ratio.num,  stream_sample_aspect_ratio.den, INT_MAX);
+    if (stream_sample_aspect_ratio.num <= 0 || stream_sample_aspect_ratio.den <= 0)
+        stream_sample_aspect_ratio = undef;
+
+    av_reduce(&frame_sample_aspect_ratio.num, &frame_sample_aspect_ratio.den,
+        frame_sample_aspect_ratio.num,  frame_sample_aspect_ratio.den, INT_MAX);
+    if (frame_sample_aspect_ratio.num <= 0 || frame_sample_aspect_ratio.den <= 0)
+        frame_sample_aspect_ratio = undef;
+
+    if (stream_sample_aspect_ratio.num)
+        return stream_sample_aspect_ratio;
+    else
+        return frame_sample_aspect_ratio;
+}
+
 double CvCapture_FFMPEG::dts_to_sec(int64_t dts)
 {
     return (double)(dts - ic->streams[video_stream]->start_time) *