ConvertedStream consider result of converter

Author: pschatzmann

src/AudioTools/AudioStreams.h

@@ -564,16 +564,17 @@ class ConvertedStream : public AudioStreamX {
         virtual int availableForWrite() { return p_stream->availableForWrite(); }
 
         virtual size_t write(const uint8_t *buffer, size_t size) { 
-           p_converter->convert((uint8_t *)buffer, size); 
-           return p_stream->write(buffer, size);
+          size_t result = p_converter->convert((uint8_t *)buffer, size); 
+          size_t result_written = p_stream->write(buffer, result);
+          return size * result_written / result;
         }
 
         size_t readBytes(uint8_t *data, size_t length) override {
            size_t result; p_stream->readBytes(data, length);
-           p_converter->convert(data, result); 
-           return result;
+           return p_converter->convert(data, result); 
         }
 
+
         /// Returns the available bytes in the buffer: to be avoided
         virtual int available() override {
           return p_stream->available();

src/AudioTools/Converter.h

@@ -352,10 +352,20 @@ class ConverterToInternalDACFormat : public  BaseConverter<T> {
 template<typename T>
 class ChannelReducer : public BaseConverter<T> {
     public:
+        ChannelReducer() = default;
+
         ChannelReducer(int channelCountOfSource, int channelCountOfTarget=1){
             from_channels = channelCountOfSource;
             to_channels = channelCountOfTarget;
         }
+
+        void setSourceChannels(int channelCountOfSource) {
+            from_channels = channelCountOfSource;
+        }
+
+        void setTargetChannels(int channelCountOfTarget) {
+            to_channels = channelCountOfTarget;
+        }
 
         size_t convert(uint8_t*src, size_t size) {
             int frame_count = size/(sizeof(T)*from_channels);