fix: iOS rotation when rescale

on iOS landscape mode corresponds to 90 or 270 degree. Current rescale
implementation will create output that is out of bounds for iOS frame.

Change-Id: I29c89402fc056714149f0ff2fe98e7b8bdf13565

src/media/video/filter_transpose.cpp

@@ -43,9 +43,14 @@ getTransposeFilter(int rotation, std::string inputName, int width, int height, i
         case 90:
         case -270:
             ss << "transpose=2";
-            if (rescale)
+           if (rescale) {
+                if (width > height)
                     ss << ", scale=w=-1:h=" << height
                         << ", pad=" << width << ":" << height << ":(ow-iw)/2";
+                else
+                    ss << ", scale=w=" << width << ":h=-1"
+                        << ", pad=" << width << ":" << height << ":0:(oh-ih)/2";
+            }
             break;
         case 180 :
         case -180 :
@@ -54,9 +59,14 @@ getTransposeFilter(int rotation, std::string inputName, int width, int height, i
         case 270 :
         case -90 :
             ss << "transpose=1";
-            if (rescale)
+            if (rescale) {
+                if (width > height)
                     ss << ", scale=w=-1:h=" << height
                         << ", pad=" << width << ":" << height << ":(ow-iw)/2";
+                else
+                    ss << ", scale=w=" << width << ":h=-1"
+                        << ", pad=" << width << ":" << height << ":0:(oh-ih)/2";
+            }
             break;
         default :
             return {};

src/media/video/video_mixer.cpp

@@ -213,7 +213,7 @@ VideoMixer::render_frame(VideoFrame& output, const VideoFrame& input,
     const constexpr char filterIn[] = "mixin";
     if (angle != source->rotation) {
         source->rotationFilter = video::getTransposeFilter(angle, filterIn,
-            frame->width(), frame->height(), frame->format(), true);
+            frame->width(), frame->height(), frame->format(), false);
         source->rotation = angle;
     }
     if (source->rotationFilter) {