video: change pixfmt used by VideoMixer

YUV420P was allocating one large buffer on Linux and 3 on OSX.
This was causing read overflows. We use YUYV422 which is packed (always one buf)

Issue: #81116
Change-Id: I76456f72c6f155d181aa533aa62cb70b92f6eff1

src/media/libav_utils.cpp

@@ -115,7 +115,7 @@ int libav_pixel_format(int fmt)
     switch (fmt) {
         case video::VIDEO_PIXFMT_BGRA: return PIXEL_FORMAT(BGRA);
         case video::VIDEO_PIXFMT_RGBA: return PIXEL_FORMAT(RGBA);
-        case video::VIDEO_PIXFMT_YUV420P: return PIXEL_FORMAT(YUV420P);
+        case video::VIDEO_PIXFMT_YUYV422: return PIXEL_FORMAT(YUYV422);
     }
     return fmt;
 }
@@ -123,7 +123,7 @@ int libav_pixel_format(int fmt)
 int ring_pixel_format(int fmt)
 {
     switch (fmt) {
-        case PIXEL_FORMAT(YUV420P): return video::VIDEO_PIXFMT_YUV420P;
+        case PIXEL_FORMAT(YUYV422): return video::VIDEO_PIXFMT_YUYV422;
     }
     return fmt;
 }

src/media/video/video_base.h

@@ -50,7 +50,7 @@ namespace ring { namespace video {
 
 enum VideoPixelFormat {
     VIDEO_PIXFMT_BGRA = -1,
-    VIDEO_PIXFMT_YUV420P = -2,
+    VIDEO_PIXFMT_YUYV422 = -2,
     VIDEO_PIXFMT_RGBA = -3,
 };
 

src/media/video/video_mixer.cpp

@@ -130,7 +130,7 @@ VideoMixer::process()
 
     VideoFrame& output = getNewFrame();
     try {
-        output.reserve(VIDEO_PIXFMT_YUV420P, width_, height_);
+        output.reserve(VIDEO_PIXFMT_YUYV422, width_, height_);
     } catch (const std::bad_alloc& e) {
         RING_ERR("VideoFrame::allocBuffer() failed");
         return;
@@ -231,6 +231,6 @@ VideoMixer::getHeight() const
 
 int
 VideoMixer::getPixelFormat() const
-{ return VIDEO_PIXFMT_YUV420P; }
+{ return VIDEO_PIXFMT_YUYV422; }
 
 }} // namespace ring::video