Add a base class to Wav{Reader,Writer} to access shared parameters.

Use it to clean up some code in audioproc_float.cc.

R=kwiberg@webrtc.org

Review URL: https://codereview.webrtc.org/1308893002 .

Cr-Commit-Position: refs/heads/master@{#9771}

webrtc/common_audio/wav_file.h

@@ -17,11 +17,23 @@
 #include <cstddef>
 #include <string>
 
+#include "webrtc/base/constructormagic.h"
+
 namespace webrtc {
 
+// Interface to provide access to WAV file parameters.
+class WavFile {
+ public:
+  virtual ~WavFile() {}
+
+  virtual int sample_rate() const = 0;
+  virtual int num_channels() const = 0;
+  virtual uint32_t num_samples() const = 0;
+};
+
 // Simple C++ class for writing 16-bit PCM WAV files. All error handling is
 // by calls to CHECK(), making it unsuitable for anything but debug code.
-class WavWriter {
+class WavWriter final : public WavFile {
  public:
   // Open a new WAV file for writing.
   WavWriter(const std::string& filename, int sample_rate, int num_channels);
@@ -35,9 +47,9 @@ class WavWriter {
   void WriteSamples(const float* samples, size_t num_samples);
   void WriteSamples(const int16_t* samples, size_t num_samples);
 
-  int sample_rate() const { return sample_rate_; }
-  int num_channels() const { return num_channels_; }
-  uint32_t num_samples() const { return num_samples_; }
+  int sample_rate() const override { return sample_rate_; }
+  int num_channels() const override { return num_channels_; }
+  uint32_t num_samples() const override { return num_samples_; }
 
  private:
   void Close();
@@ -45,10 +57,12 @@ class WavWriter {
   const int num_channels_;
   uint32_t num_samples_;  // Total number of samples written to file.
   FILE* file_handle_;  // Output file, owned by this class
+
+  DISALLOW_COPY_AND_ASSIGN(WavWriter);
 };
 
 // Follows the conventions of WavWriter.
-class WavReader {
+class WavReader final : public WavFile {
  public:
   // Opens an existing WAV file for reading.
   explicit WavReader(const std::string& filename);
@@ -61,9 +75,9 @@ class WavReader {
   size_t ReadSamples(size_t num_samples, float* samples);
   size_t ReadSamples(size_t num_samples, int16_t* samples);
 
-  int sample_rate() const { return sample_rate_; }
-  int num_channels() const { return num_channels_; }
-  uint32_t num_samples() const { return num_samples_; }
+  int sample_rate() const override { return sample_rate_; }
+  int num_channels() const override { return num_channels_; }
+  uint32_t num_samples() const override { return num_samples_; }
 
  private:
   void Close();
@@ -72,6 +86,8 @@ class WavReader {
   uint32_t num_samples_;  // Total number of samples in the file.
   uint32_t num_samples_remaining_;
   FILE* file_handle_;  // Input file, owned by this class.
+
+  DISALLOW_COPY_AND_ASSIGN(WavReader);
 };
 
 }  // namespace webrtc

webrtc/modules/audio_processing/test/audioproc_float.cc

@@ -63,6 +63,15 @@ const char kUsage[] =
     "All components are disabled by default. If any bi-directional components\n"
     "are enabled, only debug dump files are permitted.";
 
+// Returns a StreamConfig corresponding to wav_file if it's non-nullptr.
+// Otherwise returns a default initialized StreamConfig.
+StreamConfig MakeStreamConfig(const WavFile* wav_file) {
+  if (wav_file) {
+    return {wav_file->sample_rate(), wav_file->num_channels()};
+  }
+  return {};
+}
+
 }  // namespace
 
 int main(int argc, char* argv[]) {
@@ -162,21 +171,11 @@ int main(int argc, char* argv[]) {
   TickInterval accumulated_time;
   int num_chunks = 0;
 
-  const StreamConfig input_config = {
-      in_file.sample_rate(), in_buf.num_channels(),
-  };
-  const StreamConfig output_config = {
-      out_file.sample_rate(), out_buf.num_channels(),
-  };
+  const auto input_config = MakeStreamConfig(&in_file);
+  const auto output_config = MakeStreamConfig(&out_file);
+  const auto reverse_input_config = MakeStreamConfig(in_rev_file.get());
+  const auto reverse_output_config = MakeStreamConfig(out_rev_file.get());
 
-  StreamConfig reverse_input_config = {};
-  StreamConfig reverse_output_config = {};
-  if (process_reverse) {
-    reverse_input_config = {in_rev_file->sample_rate(),
-                            in_rev_file->num_channels()};
-    reverse_output_config = {out_rev_file->sample_rate(),
-                             out_rev_file->num_channels()};
-  }
   while (in_file.ReadSamples(in_interleaved.size(),
                              &in_interleaved[0]) == in_interleaved.size()) {
     // Have logs display the file time rather than wallclock time.