SoundDevice.cc

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#include "SoundDevice.hh"
 
#include "MSXMixer.hh"
#include "DeviceConfig.hh"
#include "Mixer.hh"
#include "XMLElement.hh"
#include "Filename.hh"
#include "StringOp.hh"
#include "MSXException.hh"
 
#include "narrow.hh"
#include "ranges.hh"
#include "one_of.hh"
#include "vla.hh"
#include "xrange.hh"
 
#include <array>
#include <bit>
#include <cassert>
 
namespace openmsx {
 
[[nodiscard]] static std::string makeUnique(const MSXMixer& mixer, std::string_view name)
{
        std::string result(name);
        if (mixer.findDevice(result)) {
                unsigned n = 0;
                do {
                        result = strCat(name, " (", ++n, ')');
                } while (mixer.findDevice(result));
        }
        return result;
}
 
void SoundDevice::addFill(float*& buf, float val, unsigned num)
{
        // Note: in the past we tried to optimize this by always producing
        // a multiple of 4 output values. In the general case a SoundDevice is
        // allowed to do this, but only at the end of the sound buffer. This
        // method can also be called in the middle of a buffer (so multiple
        // times per buffer), in such case it does go wrong.
        assert(num > 0);
        do {
                *buf++ += val;
        } while (--num);
}
 
SoundDevice::SoundDevice(MSXMixer& mixer_, std::string_view name_, static_string_view description_,
                         unsigned numChannels_, unsigned inputRate, bool stereo_)
        : mixer(mixer_)
        , name(makeUnique(mixer, name_))
        , description(description_)
        , numChannels(numChannels_)
        , stereo(stereo_ ? 2 : 1)
{
        assert(numChannels <= MAX_CHANNELS);
        assert(stereo == one_of(1u, 2u));
 
        setInputRate(inputRate);
 
        // initially no channels are muted
        ranges::fill(channelMuted, false);
        ranges::fill(channelBalance, 0);
}
 
SoundDevice::~SoundDevice() = default;
 
float SoundDevice::getAmplificationFactorImpl() const
{
        return 1.0f / 32768.0f;
}
 
void SoundDevice::registerSound(const DeviceConfig& config)
{
        const auto& soundConfig = config.getChild("sound");
        float volume = narrow<float>(soundConfig.getChildDataAsInt("volume", 0)) * (1.0f / 32767.0f);
        int devBalance = 0;
        std::string_view mode = soundConfig.getChildData("mode", "mono");
        if (mode == "mono") {
                devBalance = 0;
        } else if (mode == "left") {
                devBalance = -100;
        } else if (mode == "right") {
                devBalance = 100;
        } else {
                throw MSXException("balance \"", mode, "\" illegal");
        }
 
        for (const auto* b : soundConfig.getChildren("balance")) {
                auto balance = StringOp::stringTo<int>(b->getData());
                if (!balance) {
                        throw MSXException("balance ", b->getData(), " illegal");
                }
 
                const auto* channel = b->findAttribute("channel");
                if (!channel) {
                        devBalance = *balance;
                        continue;
                }
 
                // TODO Support other balances
                if (*balance != one_of(0, -100, 100)) {
                        throw MSXException("balance ", *balance, " illegal");
                }
                if (*balance != 0) {
                        balanceCenter = false;
                }
 
                auto channels = StringOp::parseRange(channel->getValue(), 1, numChannels);
                channels.foreachSetBit([&](size_t c) {
                        channelBalance[c - 1] = *balance;
                });
        }
 
        mixer.registerSound(*this, volume, devBalance, numChannels);
}
 
void SoundDevice::unregisterSound()
{
        mixer.unregisterSound(*this);
}
 
void SoundDevice::updateStream(EmuTime::param time)
{
        mixer.updateStream(time);
}
 
void SoundDevice::setSoftwareVolume(float volume, EmuTime::param time)
{
        setSoftwareVolume(volume, volume, time);
}
 
void SoundDevice::setSoftwareVolume(float left, float right, EmuTime::param time)
{
        updateStream(time);
        softwareVolumeLeft  = left;
        softwareVolumeRight = right;
        mixer.updateSoftwareVolume(*this);
}
 
void SoundDevice::recordChannel(unsigned channel, const Filename& filename)
{
        assert(channel < numChannels);
        bool wasRecording = writer[channel].has_value();
        if (!filename.empty()) {
                writer[channel].emplace(
                        filename, stereo, inputSampleRate);
        } else {
                writer[channel].reset();
        }
        bool recording = writer[channel].has_value();
        if (recording != wasRecording) {
                if (recording) {
                        if (numRecordChannels == 0) {
                                mixer.setSynchronousMode(true);
                        }
                        ++numRecordChannels;
                        assert(numRecordChannels <= numChannels);
                } else {
                        assert(numRecordChannels > 0);
                        --numRecordChannels;
                        if (numRecordChannels == 0) {
                                mixer.setSynchronousMode(false);
                        }
                }
        }
}
 
void SoundDevice::muteChannel(unsigned channel, bool muted)
{
        assert(channel < numChannels);
        channelMuted[channel] = muted;
}
 
std::span<const float> SoundDevice::getLastBuffer(unsigned channel)
{
        assert(channel < numChannels);
        auto& buf = channelBuffers[channel];
 
        buf.requestCounter = inputSampleRate; // active for ~1 second
 
        unsigned requestedSize = getLastBufferSize();
        if (buf.stopIdx < requestedSize) return {}; // not enough samples (yet)
        if (buf.silent >= requestedSize) return {}; // silent
        return {&buf.buffer[buf.stopIdx - requestedSize], requestedSize};
}
 
bool SoundDevice::mixChannels(float* dataOut, size_t samples)
{
#ifdef __SSE2__
        assert((uintptr_t(dataOut) & 15) == 0); // must be 16-byte aligned
#endif
        if (samples == 0) return true;
        size_t outputStereo = isStereo() ? 2 : 1;
 
        std::array<float*, MAX_CHANNELS> bufs_;
        auto bufs = subspan(bufs_, 0, numChannels);
 
        // TODO optimization: All channels with the same balance (according to
        // channelBalance[]) could use the same buffer when balanceCenter is
        // false
        auto needSeparateBuffer = [&](unsigned channel) {
                return channelBuffers[channel].requestCounter != 0
                    || channelMuted[channel]
                    || writer[channel]
                    || !balanceCenter;
        };
        bool anySeparateChannel = false;
        unsigned size = samples * stereo;
        unsigned padded = (size + 3) & ~3; // round up to multiple of 4
        for (auto i : xrange(numChannels)) {
                auto& cb = channelBuffers[i];
                if (!needSeparateBuffer(i)) {
                        // no need to keep this channel separate
                        bufs[i] = dataOut;
                        cb.stopIdx = 0; // no valid last data
                } else {
                        anySeparateChannel = true;
                        cb.requestCounter = std::max<int>(0, cb.requestCounter - samples);
 
                        unsigned remainingSize = cb.buffer.size() - cb.stopIdx;
                        if (remainingSize < padded) {
                                // not enough space at the tail of the buffer
                                unsigned lastBufferSize = getLastBufferSize();
                                auto allocateSize = 2 * std::max(lastBufferSize, padded);
                                if (cb.buffer.size() < allocateSize) [[unlikely]] {
                                        // increase buffer size
                                        cb.buffer.resize(allocateSize);
                                }
                                unsigned reuse = lastBufferSize >= size ? lastBufferSize - size : 0;
                                if (cb.stopIdx > reuse) {
                                        // move existing data to front
                                        memmove(&cb.buffer[0], &cb.buffer[cb.stopIdx - reuse], reuse * sizeof(float));
                                }
                                cb.stopIdx = reuse;
                        }
                        auto* ptr = &cb.buffer[cb.stopIdx];
                        bufs[i] = ptr;
                        ranges::fill(std::span{ptr, size}, 0.0f);
                        cb.stopIdx += size;
                }
        }
 
        static_assert(sizeof(float) == sizeof(uint32_t));
        if ((numChannels != 1) || anySeparateChannel) {
                // The generateChannels() method of SoundDevices with more than
                // one channel will _add_ the generated channel data in the
                // provided buffers. Those with only one channel will directly
                // replace the content of the buffer. For the former we must
                // start from a buffer containing all zeros.
                ranges::fill(std::span{dataOut, outputStereo * samples}, 0.0f);
        }
 
        generateChannels(bufs, narrow<unsigned>(samples));
 
        if (!anySeparateChannel) {
                return ranges::any_of(xrange(numChannels),
                                      [&](auto i) { return bufs[i]; });
        }
 
        for (auto i : xrange(numChannels)) {
                // record channels
                if (writer[i]) {
                        assert(bufs[i] != dataOut);
                        if (bufs[i]) {
                                auto amp = getAmplificationFactor();
                                if (stereo == 1) {
                                        writer[i]->write(
                                                std::span{bufs[i], samples},
                                                amp.left);
                                } else {
                                        writer[i]->write(
                                                std::span{std::bit_cast<const StereoFloat*>(bufs[i]), samples},
                                                amp.left, amp.right);
                                }
                        } else {
                                writer[i]->writeSilence(narrow<unsigned>(stereo * samples));
                        }
                }
                // update silent info in channelBuffers
                auto& cb = channelBuffers[i];
                if (bufs[i]) {
                        cb.silent = 0;
                } else {
                        cb.silent += samples;
                }
        }
 
        // remove muted channels (explicitly by user or by device itself)
        bool anyUnmuted = false;
        unsigned numMix = 0;
        VLA(int, mixBalance, numChannels);
        for (auto i : xrange(numChannels)) {
                if (bufs[i] && !channelMuted[i]) {
                        anyUnmuted = true;
                        if (bufs[i] != dataOut) {
                                bufs[numMix] = bufs[i];
                                mixBalance[numMix] = channelBalance[i];
                                ++numMix;
                        }
                }
        }
 
        if (numMix == 0) {
                // all extra channels muted
                return anyUnmuted;
        }
 
        // actually mix channels
        if (!balanceCenter) {
                size_t i = 0;
                do {
                        float left0  = 0.0f;
                        float right0 = 0.0f;
                        float left1  = 0.0f;
                        float right1 = 0.0f;
                        unsigned j = 0;
                        do {
                                if (mixBalance[j] <= 0) {
                                        left0  += bufs[j][i + 0];
                                        left1  += bufs[j][i + 1];
                                }
                                if (mixBalance[j] >= 0) {
                                        right0 += bufs[j][i + 0];
                                        right1 += bufs[j][i + 1];
                                }
                                j++;
                        } while (j < numMix);
                        dataOut[i * 2 + 0] = left0;
                        dataOut[i * 2 + 1] = right0;
                        dataOut[i * 2 + 2] = left1;
                        dataOut[i * 2 + 3] = right1;
                        i += 2;
                } while (i < samples);
 
                return true;
        }
 
        // In the past we had ARM and x86-SSE2 optimized assembly routines for
        // the stuff below. Currently this code is only rarely used anymore
        // (only when recording or muting individual sound chip channels), so
        // it's not worth the extra complexity anymore.
        size_t num = samples * stereo;
        size_t i = 0;
        do {
                auto out0 = dataOut[i + 0];
                auto out1 = dataOut[i + 1];
                auto out2 = dataOut[i + 2];
                auto out3 = dataOut[i + 3];
                unsigned j = 0;
                do {
                        out0 += bufs[j][i + 0];
                        out1 += bufs[j][i + 1];
                        out2 += bufs[j][i + 2];
                        out3 += bufs[j][i + 3];
                        ++j;
                } while (j < numMix);
                dataOut[i + 0] = out0;
                dataOut[i + 1] = out1;
                dataOut[i + 2] = out2;
                dataOut[i + 3] = out3;
                i += 4;
        } while (i < num);
 
        return true;
}
 
const DynamicClock& SoundDevice::getHostSampleClock() const
{
        return mixer.getHostSampleClock();
}
double SoundDevice::getEffectiveSpeed() const
{
        return mixer.getEffectiveSpeed();
}
 
} // namespace openmsx