Read input via AudioInputStream base class.

Signed-off-by: Stefan Westerfeld <stefan@space.twc.de>

src/audiostream.hh

@@ -10,12 +10,14 @@ public:
   virtual int     bit_depth()   const = 0;
   virtual int     sample_rate() const = 0;
   virtual size_t  n_frames()    const = 0;
+  virtual int     n_channels()  const = 0;
 
   virtual ~AudioStream();
 };
 
 class AudioInputStream : public AudioStream
 {
+public:
   virtual Error read_frames (std::vector<float>& samples, size_t count) = 0;
 };
 

src/audiowmark.cc

@@ -1095,13 +1095,17 @@ add_watermark (const string& infile, const string& outfile, const string& bits)
   auto bitvec_a = randomize_bit_order (conv_encode (ConvBlockType::a, bitvec), /* encode */ true);
   auto bitvec_b = randomize_bit_order (conv_encode (ConvBlockType::b, bitvec), /* encode */ true);
 
-  auto in_stream = std::make_unique<SFInputStream> (); // FIXME: need virtual constructor
-  Error err = in_stream->open (infile);
-  if (err)
-    {
-      fprintf (stderr, "audiowmark: error opening %s: %s\n", infile.c_str(), err.message());
-      return 1;
-    }
+  std::unique_ptr<AudioInputStream> in_stream; // FIXME: virtual constructor
+  {
+    SFInputStream *sistream = new SFInputStream ();
+    in_stream.reset (sistream);
+    Error err = sistream->open (infile);
+    if (err)
+      {
+        fprintf (stderr, "audiowmark: error opening %s: %s\n", infile.c_str(), err.message());
+        return 1;
+      }
+  }
   int orig_seconds = in_stream->n_frames() / in_stream->sample_rate();
   info ("Time:         %d:%02d\n", orig_seconds / 60, orig_seconds % 60);
   info ("Sample Rate:  %d\n", in_stream->sample_rate());
@@ -1113,7 +1117,7 @@ add_watermark (const string& infile, const string& outfile, const string& bits)
     {
       StdoutWavOutputStream *swstream = new StdoutWavOutputStream();
       out_stream.reset (swstream);
-      err = swstream->open (in_stream->n_channels(), in_stream->sample_rate(), out_bit_depth, in_stream->n_frames());
+      Error err = swstream->open (in_stream->n_channels(), in_stream->sample_rate(), out_bit_depth, in_stream->n_frames());
       if (err)
         {
           error ("audiowmark: error writing to -: %s\n", err.message());

src/sfoutputstream.cc

@@ -99,6 +99,12 @@ SFOutputStream::sample_rate() const
   return m_sample_rate;
 }
 
+int
+SFOutputStream::n_channels() const
+{
+  return m_n_channels;
+}
+
 size_t
 SFOutputStream::n_frames() const
 {

src/sfoutputstream.hh

@@ -31,6 +31,7 @@ public:
   void   close();
   int    bit_depth() const override;
   int    sample_rate() const override;
+  int    n_channels() const override;
   size_t n_frames() const override;
 };
 

src/stdoutwavoutputstream.cc

@@ -24,6 +24,12 @@ StdoutWavOutputStream::bit_depth() const
   return m_bit_depth;
 }
 
+int
+StdoutWavOutputStream::n_channels() const
+{
+  return m_n_channels;
+}
+
 static void
 header_append_str (vector<unsigned char>& bytes, const string& str)
 {

src/stdoutwavoutputstream.hh

@@ -10,6 +10,7 @@ class StdoutWavOutputStream : public AudioOutputStream
   std::string m_error_blurb;
   int         m_bit_depth = 0;
   int         m_sample_rate = 0;
+  int         m_n_channels = 0;
   size_t      m_n_frames = 0;
   size_t      m_close_padding = 0;
 
@@ -28,6 +29,7 @@ public:
   void close();
   int  sample_rate() const override;
   int  bit_depth() const override;
+  int  n_channels() const override;
   size_t n_frames() const override
   {
     return m_n_frames;