Function read_wav_f32

src/framework/audio/wav_reader.cpp:30–114

        }
        char * base = eback();
        char * next = gptr();
        char * end = egptr();
        char * target = nullptr;
        if (dir == std::ios_base::beg) {
            target = base + offset;
        } else if (dir == std::ios_base::cur) {
            target = next + offset;
        } else if (dir == std::ios_base::end) {
            target = end + offset;
        }
        if (target == nullptr || target < base || target > end) {
            return pos_type(off_type(-1));
        }
        setg(base, target, end);
        return pos_type(target - base);
    }

    pos_type seekpos(pos_type position, std::ios_base::openmode which) override {
        return seekoff(off_type(position), std::ios_base::beg, which);
    }
};

template <typename T>
T read_scalar(std::istream & input) {
    T value{};
    input.read(reinterpret_cast<char *>(&value), sizeof(T));
    if (!input) {
        throw std::runtime_error("failed to read WAV scalar");
    }
    return value;
}

void skip_bytes(std::istream & input, std::streamoff count) {
    input.seekg(count, std::ios::cur);
    if (!input) {
        throw std::runtime_error("failed to seek inside WAV file");
    }
}

// WAVE format tags. EXTENSIBLE is the one that matters in practice: many
// encoders emit it for ordinary PCM16 whenever there are more than two channels
// or a channel mask is set, and the real codec then lives in a SubFormat GUID
// rather than in the format tag itself.
constexpr uint16_t kFormatPcm = 0x0001;
constexpr uint16_t kFormatFloat = 0x0003;
constexpr uint16_t kFormatALaw = 0x0006;
constexpr uint16_t kFormatMuLaw = 0x0007;
constexpr uint16_t kFormatExtensible = 0xFFFE;

// Bytes 2..15 of every KSDATAFORMAT_SUBTYPE_* GUID:
// XXXXXXXX-0000-0010-8000-00aa00389b71.
constexpr std::array<char, 14> kKsDataFormatSubtypeTail = {
    0x00, 0x00, 0x00, 0x00, 0x10, 0x00, static_cast<char>(0x80),
    0x00, 0x00, static_cast<char>(0xAA), 0x00, 0x38, static_cast<char>(0x9B), 0x71,
};

// Names a container we can recognise but not decode, so the error can say what
// the file actually is instead of "invalid WAV RIFF header".