tangara-fw/src/codecs/include/codec.hpp

#pragma once

#include <stdint.h>
#include <cstddef>
#include <cstdint>

#include "result.hpp"

namespace codecs {

  enum CreateCodecError {
    UNKNOWN_EXTENSION
  };

  auto CreateCodecForExtension(std::string extension) -> cpp::result<std::unique_ptr<ICodec>, CreateCodecError>;

  class ICodec {
    public:
      virtual ~ICodec() {}

      virtual auto CanHandleExtension(std::string extension) -> bool = 0;

      struct OutputFormat {
        uint8_t num_channels;
        uint8_t bits_per_sample;
        int sample_rate_hz;
      };

      virtual auto GetOutputFormat() -> OutputFormat = 0;

      enum Error {};

      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;
      };

      virtual auto Process(
          uint8_t *input,
          std::size_t input_len,
          uint8_t *output,
	  std::size_t output_length) -> cpp::result<Result, Error>  = 0;
  };

} // namespace codecs