Unify output stream creation.

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

src/audiostream.cc

 #include "audiostream.hh"
 #include "wmcommon.hh"
 #include "sfinputstream.hh"
+#include "sfoutputstream.hh"
 #include "mp3.hh"
 #include "mp3inputstream.hh"
 #include "rawconverter.hh"
+#include "rawoutputstream.hh"
+#include "stdoutwavoutputstream.hh"
 
 using std::string;
 
@@ -44,3 +47,35 @@ AudioInputStream::create (const string& filename, Error& err)
     }
   return in_stream;
 }
+
+std::unique_ptr<AudioOutputStream>
+AudioOutputStream::create (const string& filename, int n_channels, int sample_rate, int bit_depth, size_t n_frames, Error& err)
+{
+  std::unique_ptr<AudioOutputStream> out_stream;
+
+  if (Params::output_format == Format::RAW)
+    {
+      RawOutputStream *rostream = new RawOutputStream();
+      out_stream.reset (rostream);
+      err = rostream->open (filename, Params::raw_output_format);
+      if (err)
+        return nullptr;
+    }
+  else if (filename == "-")
+    {
+      StdoutWavOutputStream *swstream = new StdoutWavOutputStream();
+      out_stream.reset (swstream);
+      err = swstream->open (n_channels, sample_rate, bit_depth, n_frames);
+      if (err)
+        return nullptr;
+    }
+  else
+    {
+      SFOutputStream *sfostream = new SFOutputStream();
+      out_stream.reset (sfostream);
+      err = sfostream->open (filename, n_channels, sample_rate, bit_depth, n_frames);
+      if (err)
+        return nullptr;
+    }
+  return out_stream;
+}

src/audiostream.hh

@@ -30,6 +30,9 @@ public:
 class AudioOutputStream : public AudioStream
 {
 public:
+  static std::unique_ptr<AudioOutputStream> create (const std::string& filename,
+    int n_channels, int sample_rate, int bit_depth, size_t n_frames, Error& err);
+
   virtual Error write_frames (const std::vector<float>& frames) = 0;
   virtual Error close() = 0;
 };

src/wavdata.cc

@@ -63,19 +63,19 @@ WavData::load (AudioInputStream *in_stream)
 Error
 WavData::save (const string& filename)
 {
-  std::unique_ptr<AudioOutputStream> out_stream; // FIXME: virtual constructor
+  std::unique_ptr<AudioOutputStream> out_stream;
+  Error err;
 
-  SFOutputStream *sostream = new SFOutputStream();
-  out_stream.reset (sostream);
-  Error err = sostream->open (filename, m_n_channels, m_sample_rate, m_bit_depth, m_samples.size() / m_n_channels);
+  out_stream = AudioOutputStream::create (filename, m_n_channels, m_sample_rate, m_bit_depth, m_samples.size() / m_n_channels, err);
   if (err)
     return err;
 
-  err = sostream->write_frames (m_samples);
+  err = out_stream->write_frames (m_samples);
   if (err)
     return err;
 
-  return Error::Code::NONE;
+  err = out_stream->close();
+  return err;
 }
 
 int

src/wmadd.cc

@@ -614,38 +614,11 @@ add_watermark (const string& infile, const string& outfile, const string& bits)
 
   const int out_bit_depth = in_stream->bit_depth() > 16 ? 24 : 16;
   std::unique_ptr<AudioOutputStream> out_stream;
-  if (Params::output_format == Format::RAW)
-    {
-      RawOutputStream *rostream = new RawOutputStream();
-      out_stream.reset (rostream);
-      err = rostream->open (outfile, Params::raw_output_format);
-      if (err)
-        {
-          error ("audiowmark: error opening %s: %s\n", outfile.c_str(), err.message());
-          return 1;
-        }
-    }
-  else if (outfile == "-")
-    {
-      StdoutWavOutputStream *swstream = new StdoutWavOutputStream();
-      out_stream.reset (swstream);
-      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());
-          return 1;
-        }
-    }
-  else
+  out_stream = AudioOutputStream::create (outfile, in_stream->n_channels(), in_stream->sample_rate(), out_bit_depth, in_stream->n_frames(), err);
+  if (err)
     {
-      SFOutputStream *sfostream = new SFOutputStream();
-      out_stream.reset (sfostream);
-      Error err = sfostream->open (outfile, in_stream->n_channels(), in_stream->sample_rate(), out_bit_depth, in_stream->n_frames());
-      if (err)
-        {
-          error ("audiowmark: error writing to %s: %s\n", outfile.c_str(), err.message());
-          return 1;
-        }
+      error ("audiowmark: error writing to %s: %s\n", outfile.c_str(), err.message());
+      return 1;
     }
 
   if (out_stream->sample_rate() != in_stream->sample_rate())