introduce channelCount for Audio/VideoFrame

src/AudioFrame.cpp

@@ -103,6 +103,14 @@ AudioFrame::~AudioFrame()
 {
 }
 
+int AudioFrame::channelCount() const
+{
+    Q_D(const AudioFrame);
+    if (!d->format.isValid())
+        return 0;
+    return d->format.channels();
+}
+
 AudioFrame AudioFrame::clone() const
 {
     Q_D(const AudioFrame);

src/Frame.cpp

@@ -134,6 +134,10 @@ int Frame::planeCount() const
     return d->planes.size();
 }
 
+int Frame::channelCount() const
+{
+    return planeCount();
+}
 
 /*!
     Returns any extra metadata associated with this frame.

src/QtAV/AudioFrame.h

@@ -41,6 +41,7 @@ class Q_AV_EXPORT AudioFrame : public Frame
 
     AudioFrame &operator =(const AudioFrame &other);
 
+    virtual int channelCount() const;
     /*!
      * Deep copy. If you want to copy data from somewhere, knowing the format, width and height,
      * then you can use clone().

src/QtAV/Frame.h

@@ -41,14 +41,21 @@ class Q_AV_EXPORT Frame
     // allocate memory with given format and other information
     virtual int allocate();
     /*!
-     * \brief bytesPerLine
+     * \brief planeCount
      *  a decoded frame can be packed and planar. packed format has only 1 plane, while planar
      *  format has more than 1 plane. For audio, the number plane equals channel count. For
      *  video, rgb is 1 plane, yuv420p is 3 plane, p means planar
      * \param plane default is the first plane
      * \return
      */
     int planeCount() const;
+    /*!
+     * \brief channelCount
+     * for audio, channel count equals plane count
+     * for video, channels >= planes
+     * \return
+     */
+    virtual int channelCount() const;
     /*!
      * \brief bytesPerLine
      *   For video, it's size of each picture line. For audio, it's the whole size of plane

src/QtAV/VideoFrame.h

@@ -48,6 +48,7 @@ class Q_AV_EXPORT VideoFrame : public Frame
 
     VideoFrame &operator =(const VideoFrame &other);
 
+    virtual int channelCount() const;
     /*!
      * Deep copy. Given the format, width and height, plane addresses and line sizes.
      */

src/VideoFrame.cpp

@@ -182,6 +182,14 @@ VideoFrame::~VideoFrame()
 {
 }
 
+int VideoFrame::channelCount() const
+{
+    Q_D(const VideoFrame);
+    if (!d->format.isValid())
+        return 0;
+    return d->format.channels();
+}
+
 VideoFrame VideoFrame::clone() const
 {
     Q_D(const VideoFrame);