src/media/audio/tools/audio-driver-ctl/wav-common.h

// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SRC_MEDIA_AUDIO_TOOLS_AUDIO_DRIVER_CTL_WAV_COMMON_H_
#define SRC_MEDIA_AUDIO_TOOLS_AUDIO_DRIVER_CTL_WAV_COMMON_H_

#include <endian.h>
#include <zircon/compiler.h>
#include <zircon/types.h>

namespace internal {
static inline constexpr uint32_t make_fourcc(uint8_t a, uint8_t b, uint8_t c, uint8_t d) {
  return (static_cast<uint32_t>(d) << 24) | (static_cast<uint32_t>(c) << 16) |
         (static_cast<uint32_t>(b) << 8) | static_cast<uint32_t>(a);
}
}  // namespace internal

class WAVCommon {
 public:
  WAVCommon() {}
  virtual ~WAVCommon() { Close(); }

 protected:
  struct __PACKED RIFFChunkHeader {
    uint32_t four_cc;
    uint32_t length;

    void FixupEndian() {
      four_cc = htole32(four_cc);
      length = htole32(length);
    }
  };

  struct __PACKED WAVHeader {
    uint32_t wave_four_cc;
    uint32_t fmt_four_cc;
    uint32_t fmt_chunk_len;
    uint16_t format;
    uint16_t channel_count;
    uint32_t frame_rate;
    uint32_t average_byte_rate;
    uint16_t frame_size;
    uint16_t bits_per_sample;

    void FixupEndian() {
      wave_four_cc = htole32(wave_four_cc);
      fmt_four_cc = htole32(fmt_four_cc);
      fmt_chunk_len = htole32(fmt_chunk_len);
      format = htole16(format);
      channel_count = htole16(channel_count);
      frame_rate = htole32(frame_rate);
      average_byte_rate = htole32(average_byte_rate);
      frame_size = htole16(frame_size);
      bits_per_sample = htole16(bits_per_sample);
    }
  };

  enum class InitMode { SOURCE, SINK };
  zx_status_t Initialize(const char* filename, InitMode mode);

  static constexpr uint32_t RIFF_FOUR_CC = internal::make_fourcc('R', 'I', 'F', 'F');
  static constexpr uint32_t WAVE_FOUR_CC = internal::make_fourcc('W', 'A', 'V', 'E');
  static constexpr uint32_t FMT_FOUR_CC = internal::make_fourcc('f', 'm', 't', ' ');
  static constexpr uint32_t DATA_FOUR_CC = internal::make_fourcc('d', 'a', 't', 'a');

  // WAV/AVI format codes are defined in RFC 2361.  Also, the list goes on for
  // 55 pages, so we don't list the vast majority of them here.
  static constexpr uint16_t FORMAT_UNKNOWN = 0x0000;
  static constexpr uint16_t FORMAT_LPCM = 0x0001;
  static constexpr uint16_t FORMAT_MSFT_ADPCM = 0x0002;
  static constexpr uint16_t FORMAT_IEEE_FLOAT = 0x0003;
  static constexpr uint16_t FORMAT_MSFT_ALAW = 0x0006;
  static constexpr uint16_t FORMAT_MSFT_MULAW = 0x0007;

  void Close();
  zx_status_t Read(void* buf, size_t len);
  zx_status_t Write(const void* buf, size_t len);
  zx_status_t Seek(off_t abs_pos);

  int fd_ = -1;
};

#endif  // SRC_MEDIA_AUDIO_TOOLS_AUDIO_DRIVER_CTL_WAV_COMMON_H_