fix build errors

2 files changed, 54 insertions, 36 deletions

diff --git a/src/codecs/include/codec.hpp b/src/codecs/include/codec.hpp
index 8e82bd71..764b63fc 100644
--- a/src/codecs/include/codec.hpp
+++ b/src/codecs/include/codec.hpp
@@ -1,18 +1,17 @@
 #pragma once
 
 #include <stdint.h>
+
 #include <cstddef>
 #include <cstdint>
+#include <memory>
+#include <string>
+#include <utility>
 
 #include "result.hpp"
 
 namespace codecs {
 
-enum CreateCodecError { UNKNOWN_EXTENSION };
-
-auto CreateCodecForFile(const std::string& extension)
-    -> cpp::result<std::unique_ptr<ICodec>, CreateCodecError>;
-
 class ICodec {
  public:
   virtual ~ICodec() {}
@@ -22,39 +21,48 @@ class ICodec {
   struct OutputFormat {
     uint8_t num_channels;
     uint8_t bits_per_sample;
-    int sample_rate_hz;
+    uint32_t sample_rate_hz;
   };
 
   virtual auto GetOutputFormat() -> OutputFormat = 0;
 
-  enum ProcessingError {};
-
-  struct Result {
-    bool need_more_input;
-    /*
-     * For need_more_input, this is how far we got in the input buffer
-     * before we were unable to process more data. Any remaining data in the
-     * buffer should be moved to the start before the next call.
-     */
-    std::size_t input_processed;
-
-    bool flush_output;
-    /*
-     * For flush_output, this is how far we got in the output buffer before
-     * we ran out of space for samples. The caller should flush this many
-     * bytes downstream.
-     */
-    std::size_t output_written;
-  };
+  enum ProcessingError { MALFORMED_DATA };
 
   virtual auto ResetForNewStream() -> void = 0;
 
-  virtual auto SetInput(uint8_t* buffer, std::size_t length) = 0;
-  virtual auto Process(uint8_t* output, std::size_t output_length)
-      -> cpp::result<size_t, Error> = 0;
-
-  virtual auto GetOutputProcessed() -> std::size_t;
-  = 0;
+  virtual auto SetInput(uint8_t* buffer, std::size_t length) -> void = 0;
+
+  /*
+   * Returns the codec's next read position within the input buffer. If the
+   * codec is out of usable data, but there is still some data left in the
+   * stream, that data should be prepended to the next input buffer.
+   */
+  virtual auto GetInputPosition() -> std::size_t = 0;
+
+  /*
+   * Read one frame (or equivalent discrete chunk) from the input, and
+   * synthesize output samples for it.
+   *
+   * Returns true if we are out of usable data from the input stream, or false
+   * otherwise.
+   */
+  virtual auto ProcessNextFrame() -> cpp::result<bool, ProcessingError> = 0;
+
+  /*
+   * Writes PCM samples to the given output buffer.
+   *
+   * Returns the number of bytes that were written, and true if all of the
+   * samples synthesized from the last call to `ProcessNextFrame` have been
+   * written. If this returns false, then this method should be called again
+   * after flushing the output buffer.
+   */
+  virtual auto WriteOutputSamples(uint8_t* output, std::size_t output_length)
+      -> std::pair<std::size_t, bool> = 0;
 };
 
+enum CreateCodecError { UNKNOWN_EXTENSION };
+
+auto CreateCodecForFile(const std::string& extension)
+    -> cpp::result<std::unique_ptr<ICodec>, CreateCodecError>;
+
 }  // namespace codecs
diff --git a/src/codecs/include/mad.hpp b/src/codecs/include/mad.hpp
index 241ea6c3..aa24f3c9 100644
--- a/src/codecs/include/mad.hpp
+++ b/src/codecs/include/mad.hpp
@@ -1,5 +1,11 @@
 #pragma once
 
+#include <cstddef>
+#include <cstdint>
+#include <string>
+
+#include "mad.h"
+
 #include "codec.hpp"
 
 namespace codecs {
@@ -9,10 +15,14 @@ class MadMp3Decoder : public ICodec {
   MadMp3Decoder();
   ~MadMp3Decoder();
 
-  auto ProcessInput(Result* res, uint8_t* input, std::size_t input_len) -> void;
-  auto WriteOutputSamples(Result* res,
-                          uint8_t* output,
-                          std::size_t output_length) -> void;
+  auto CanHandleFile(const std::string& path) -> bool override;
+  auto GetOutputFormat() -> OutputFormat override;
+  auto ResetForNewStream() -> void override;
+  auto SetInput(uint8_t* buffer, std::size_t length) -> void override;
+  auto GetInputPosition() -> std::size_t override;
+  auto ProcessNextFrame() -> cpp::result<bool, ProcessingError> override;
+  auto WriteOutputSamples(uint8_t* output, std::size_t output_length)
+      -> std::pair<std::size_t, bool> override;
 
  private:
   mad_stream stream_;
@@ -22,7 +32,7 @@ class MadMp3Decoder : public ICodec {
   mad_header header_;
   bool has_decoded_header_;
 
-  int current_sample_ = -1;
+  int current_sample_;
 };
 
 }  // namespace codecs