Don't read more than the buffer size.

    }

    // maxBytesToRead may be reduced so that in-place data conversion will fit in buffer size.

    const size_t bufferSize = buffer->size();

    const size_t bufferSize = std::min(buffer->size(), kMaxFrameSize);

    size_t maxBytesToRead;

    if (mOutputFloat) { // destination is float at 4 bytes per sample, source may be less.

        maxBytesToRead = (mBitsPerSample / 8) * (bufferSize / 4);