lavu/stereo3d: change the horizontal FOV field to a rational

This avoids hardcoding any implementation-specific limitiations as
part of the API, and allows for future expandability.

This also allows API users to more conveniently convert the
values into floats without hardcoding specific conversion constants.

The API was committed a few days ago, so changing this field now
is within the realms of acceptable.

fftools/ffprobe.c

@@ -2548,7 +2548,7 @@ static void print_pkt_side_data(WriterContext *w,
             print_str("primary_eye", av_stereo3d_primary_eye_name(stereo->primary_eye));
             print_int("baseline", stereo->baseline);
             print_q("horizontal_disparity_adjustment", stereo->horizontal_disparity_adjustment, '/');
-            print_int("horizontal_field_of_view", stereo->horizontal_field_of_view);
+            print_q("horizontal_field_of_view", stereo->horizontal_field_of_view, '/');
         } else if (sd->type == AV_PKT_DATA_SPHERICAL) {
             const AVSphericalMapping *spherical = (AVSphericalMapping *)sd->data;
             print_str("projection", av_spherical_projection_name(spherical->projection));

libavformat/dump.c

@@ -267,8 +267,9 @@ static void dump_stereo3d(void *ctx, const AVPacketSideData *sd, int log_level)
     if (stereo->horizontal_disparity_adjustment.num && stereo->horizontal_disparity_adjustment.den)
         av_log(ctx, log_level, ", horizontal_disparity_adjustment: %d/%d",
                stereo->horizontal_disparity_adjustment.num, stereo->horizontal_disparity_adjustment.den);
-    if (stereo->horizontal_field_of_view)
-        av_log(ctx, log_level, ", horizontal_field_of_view: %"PRIu32"", stereo->horizontal_field_of_view);
+    if (stereo->horizontal_field_of_view.num && stereo->horizontal_field_of_view.den)
+        av_log(ctx, log_level, ", horizontal_field_of_view: %d/%d", stereo->horizontal_field_of_view.num,
+               stereo->horizontal_field_of_view.den);
 
     if (stereo->flags & AV_STEREO3D_FLAG_INVERT)
         av_log(ctx, log_level, " (inverted)");

libavformat/mov.c

@@ -6782,7 +6782,8 @@ static int mov_read_hfov(MOVContext *c, AVIOContext *pb, MOVAtom atom)
             return AVERROR(ENOMEM);
     }
 
-    sc->stereo3d->horizontal_field_of_view = avio_rb32(pb);
+    sc->stereo3d->horizontal_field_of_view.num = avio_rb32(pb);
+    sc->stereo3d->horizontal_field_of_view.den = 1000; // thousands of a degree
 
     return 0;
 }

libavutil/stereo3d.c

@@ -29,6 +29,7 @@
 static void get_defaults(AVStereo3D *stereo)
 {
     stereo->horizontal_disparity_adjustment = (AVRational) { 0, 1 };
+    stereo->horizontal_field_of_view = (AVRational) { 0, 1 };
 }
 
 AVStereo3D *av_stereo3d_alloc(void)

libavutil/stereo3d.h

@@ -224,9 +224,9 @@ typedef struct AVStereo3D {
     AVRational horizontal_disparity_adjustment;
 
     /**
-     * Horizontal field of view in thousanths of a degree. Zero if unset.
+     * Horizontal field of view, in degrees. Zero if unset.
      */
-    uint32_t horizontal_field_of_view;
+    AVRational horizontal_field_of_view;
 } AVStereo3D;
 
 /**

tests/ref/fate/matroska-spherical-mono

@@ -7,7 +7,7 @@ view=packed
 primary_eye=none
 baseline=0
 horizontal_disparity_adjustment=0/1
-horizontal_field_of_view=0
+horizontal_field_of_view=0/1
 [/SIDE_DATA]
 [SIDE_DATA]
 side_data_type=Spherical Mapping

tests/ref/fate/matroska-spherical-mono-remux

@@ -31,7 +31,7 @@ view=packed
 primary_eye=none
 baseline=0
 horizontal_disparity_adjustment=0/1
-horizontal_field_of_view=0
+horizontal_field_of_view=0/1
 [/SIDE_DATA]
 [SIDE_DATA]
 side_data_type=Spherical Mapping
@@ -60,7 +60,7 @@ view=packed
 primary_eye=none
 baseline=0
 horizontal_disparity_adjustment=0/1
-horizontal_field_of_view=0
+horizontal_field_of_view=0/1
 [/SIDE_DATA]
 [SIDE_DATA]
 side_data_type=Spherical Mapping

tests/ref/fate/matroska-stereo_mode

@@ -136,7 +136,7 @@ view=packed
 primary_eye=none
 baseline=0
 horizontal_disparity_adjustment=0/1
-horizontal_field_of_view=0
+horizontal_field_of_view=0/1
 [/SIDE_DATA]
 [/STREAM]
 [STREAM]
@@ -156,7 +156,7 @@ view=packed
 primary_eye=none
 baseline=0
 horizontal_disparity_adjustment=0/1
-horizontal_field_of_view=0
+horizontal_field_of_view=0/1
 [/SIDE_DATA]
 [/STREAM]
 [STREAM]
@@ -174,7 +174,7 @@ view=packed
 primary_eye=none
 baseline=0
 horizontal_disparity_adjustment=0/1
-horizontal_field_of_view=0
+horizontal_field_of_view=0/1
 [/SIDE_DATA]
 [/STREAM]
 [STREAM]
@@ -193,7 +193,7 @@ view=packed
 primary_eye=none
 baseline=0
 horizontal_disparity_adjustment=0/1
-horizontal_field_of_view=0
+horizontal_field_of_view=0/1
 [/SIDE_DATA]
 [/STREAM]
 [STREAM]

tests/ref/fate/matroska-vp8-alpha-remux

@@ -39,6 +39,6 @@ view=packed
 primary_eye=none
 baseline=0
 horizontal_disparity_adjustment=0/1
-horizontal_field_of_view=0
+horizontal_field_of_view=0/1
 [/SIDE_DATA]
 [/STREAM]

tests/ref/fate/mov-spherical-mono

@@ -7,7 +7,7 @@ view=packed
 primary_eye=none
 baseline=0
 horizontal_disparity_adjustment=0/1
-horizontal_field_of_view=0
+horizontal_field_of_view=0/1
 [/SIDE_DATA]
 [SIDE_DATA]
 side_data_type=Spherical Mapping