Fill in frame duration from sample meta

If sample duration is not available, use the average
frame duration of the sequence; if that's not available
default to 30fps.

bug: 120414514
bug: 139815242
test: test some 25fps heif sequence files, the reported
      duration should be 40ms instead of the default 33ms.

Change-Id: I5ddf0a6cbfb44021dee2955badf3f2772586bb1e
diff --git a/include/private/media/VideoFrame.h b/include/private/media/VideoFrame.h
index 712f118..16e794a 100644
--- a/include/private/media/VideoFrame.h
+++ b/include/private/media/VideoFrame.h
@@ -41,7 +41,7 @@
             uint32_t angle, uint32_t bpp, bool hasData, size_t iccSize):
         mWidth(width), mHeight(height),
         mDisplayWidth(displayWidth), mDisplayHeight(displayHeight),
-        mTileWidth(tileWidth), mTileHeight(tileHeight),
+        mTileWidth(tileWidth), mTileHeight(tileHeight), mDurationUs(0),
         mRotationAngle(angle), mBytesPerPixel(bpp), mRowBytes(bpp * width),
         mSize(hasData ? (bpp * width * height) : 0),
         mIccSize(iccSize), mReserved(0) {
@@ -78,6 +78,7 @@
     uint32_t mDisplayHeight;   // Display height before rotation
     uint32_t mTileWidth;       // Tile width (0 if image doesn't have grid)
     uint32_t mTileHeight;      // Tile height (0 if image doesn't have grid)
+    int64_t  mDurationUs;      // Frame duration in microseconds
     int32_t  mRotationAngle;   // Rotation angle, clockwise, should be multiple of 90
     uint32_t mBytesPerPixel;   // Number of bytes per pixel
     uint32_t mRowBytes;        // Number of bytes per row before rotation