First implementation of JackStream

CMakeLists.txt

@@ -96,6 +96,7 @@ option(BUILD_WITH_OPUS "Build with OPUS support" ON)
 option(BUILD_WITH_AVAHI "Build with AVAHI support" ON)
 option(BUILD_WITH_EXPAT "Build with EXPAT support" ON)
 option(BUILD_WITH_PULSE "Build with PulseAudio support" ON)
+option(BUILD_WITH_JACK "Build with JACK support" ON)
 
 if(NOT BUILD_SHARED_LIBS AND NOT BUILD_STATIC_LIBS)
   message(
@@ -200,6 +201,13 @@ if(NOT WIN32 AND NOT ANDROID)
       add_compile_definitions(HAS_ALSA)
     endif(ALSA_FOUND)
 
+    if(BUILD_WITH_JACK)
+      pkg_search_module(JACK jack)
+      if(JACK_FOUND)
+        add_compile_definitions(HAS_JACK)
+      endif(JACK_FOUND)
+    endif(BUILD_WITH_JACK)
+
     if(BUILD_WITH_PULSE)
       pkg_search_module(PULSE libpulse)
       if(PULSE_FOUND)

common/message/pcm_chunk.hpp

@@ -128,6 +128,12 @@ public:
     //     payloadSize = newSize;
     // }
 
+    void setFrameCount(int frameCount) {
+        auto newSize = format.frameSize() * frameCount;
+        payload = (char*)realloc(payload, newSize);
+        payloadSize = newSize;
+    }
+
     double durationMs() const
     {
         return static_cast<double>(getFrameCount()) / format.msRate();

server/CMakeLists.txt

@@ -96,6 +96,12 @@ else()
     list(APPEND SERVER_INCLUDE ${ALSA_INCLUDE_DIRS})
   endif(ALSA_FOUND)
 
+  if(JACK_FOUND)
+    list(APPEND SERVER_SOURCES streamreader/jack_stream.cpp)
+    list(APPEND SERVER_LIBRARIES ${JACK_LIBRARIES})
+    list(APPEND SERVER_INCLUDE ${JACK_INCLUDE_DIRS})
+  endif(JACK_FOUND)
+
   if(EXPAT_FOUND)
     list(APPEND SERVER_LIBRARIES ${EXPAT_LIBRARIES})
     list(APPEND SERVER_INCLUDE ${EXPAT_INCLUDE_DIRS})

server/streamreader/jack_stream.cpp

@@ -0,0 +1,453 @@
+/***
+    This file is part of snapcast
+    Copyright (C) 2014-2024  Johannes Pohl
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+***/
+
+// prototype/interface header file
+#include "jack_stream.hpp"
+
+#include <jack/jack.h>
+
+// local headers
+#include "common/aixlog.hpp"
+#include "common/snap_exception.hpp"
+#include "common/str_compat.hpp"
+
+// standard headers
+#include <cerrno>
+#include <memory>
+
+using namespace std;
+using namespace std::chrono_literals;
+
+namespace streamreader
+{
+
+static constexpr auto LOG_TAG = "JackStream";
+
+
+void float_to_s32(char *dst, jack_default_audio_sample_t *src, unsigned long nsamples, unsigned long dst_skip)
+{
+	while (nsamples--) {
+        // float to S32 conversion
+		double clipped = fmin(1.0f, fmax((double)(*src), -1.0f));
+		double scaled = clipped * 2147483647.0;
+		*(int32_t *)dst = lrint(scaled);
+
+		dst += dst_skip;
+		src++;
+	}
+}
+
+void float_to_s24(char *dst, jack_default_audio_sample_t *src, unsigned long nsamples, unsigned long dst_skip)
+{
+    int32_t tmp;
+
+	while (nsamples--) {
+
+        // float to S24 conversion
+        if (*src <= -1.0f) {
+            tmp = -8388607;
+        } else if (*src >= 1.0f) {
+            tmp = 8388607;
+        } else {
+            tmp = lrintf (*src * 8388607.0);
+        }
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+		memcpy (dst, &tmp, 3);
+#elif __BYTE_ORDER == __BIG_ENDIAN
+		memcpy (dst, (char *)&tmp + 1, 3);
+#endif
+		dst += dst_skip;
+		src++;
+	}
+}
+
+void float_to_s16(char *dst, jack_default_audio_sample_t *src, unsigned long nsamples, unsigned long dst_skip)	
+{
+	while (nsamples--) {
+
+        // float to S16 conversion
+        if (*src <= -1.0f) {
+            *((int16_t*) dst) = -32767;
+        } else if (*src >= 1.0f) {
+            *((int16_t*) dst) = 32767;
+        } else {
+            *((int16_t*) dst) = lrintf (*src * 32767.0);
+        }
+
+		dst += dst_skip;
+		src++;
+	}
+}
+
+namespace
+{
+template <typename Rep, typename Period>
+void wait(boost::asio::steady_timer& timer, const std::chrono::duration<Rep, Period>& duration, std::function<void()> handler)
+{
+    timer.expires_after(duration);
+    timer.async_wait(
+        [handler = std::move(handler)](const boost::system::error_code& ec)
+        {
+        if (ec)
+        {
+            LOG(ERROR, LOG_TAG) << "Error during async wait: " << ec.message() << "\n";
+        }
+        else
+        {
+            handler();
+        }
+    });
+}
+} // namespace
+
+JackStream::JackStream(PcmStream::Listener* pcmListener, boost::asio::io_context& ioc, const ServerSettings& server_settings, const StreamUri& uri)
+    : PcmStream(pcmListener, ioc, server_settings, uri), read_timer_(strand_), silence_(0ms)
+{
+    send_silence_ = (uri_.getQuery("send_silence", "false") == "true");
+    idle_threshold_ = std::chrono::milliseconds(std::max(cpt::stoi(uri_.getQuery("idle_threshold", "100")), 10));
+
+    doAutoConnect_ = (uri_.query.find("autoconnect") != uri_.query.end());
+    autoConnectRegex_ = uri_.getQuery("autoconnect", "");
+    autoConnectSkip_ = cpt::stoi(uri_.getQuery("autoconnect_skip", "0"));
+
+    switch(sampleFormat_.bits())
+    {
+        case 16:
+            interleave_func_ = float_to_s16;
+            break;
+        case 24:
+            interleave_func_ = float_to_s24;
+            break;
+        case 32:
+            interleave_func_ = float_to_s32;
+            break;
+        default:
+            throw SnapException("JackStreams only support 16, 24 and 32 bit sample formats");
+    }
+
+    jack_set_error_function(jackErrorMessage);
+    jack_set_info_function(jackInfoMessage);
+}
+
+
+void JackStream::start()
+{
+    LOG(TRACE, LOG_TAG) << "JackStream::start()\n";
+
+    boost::asio::post(strand_, [this] { tryConnect(); });
+}
+
+
+void JackStream::stop()
+{
+    LOG(TRACE, LOG_TAG) << "JackStream::stop()\n";
+
+    PcmStream::stop();
+    closeJackConnection();
+}
+
+
+/**
+ * Try to connect to the jack server. If it fails, wait 
+ * a little bit and try again.
+ */
+void JackStream::tryConnect()
+{
+    try {
+        if (!openJackConnection()) {
+            LOG(WARNING, LOG_TAG) << "Jack connection failed, trying again in 5 seconds\n";
+            wait(read_timer_, 5s, [this] { tryConnect(); });
+            return;
+        }
+
+        if (!createJackPorts()) {
+            LOG(ERROR, LOG_TAG) << "Failed to create Jack ports, trying again in 5 seconds\n";
+            closeJackConnection();
+            wait(read_timer_, 5s, [this] { tryConnect(); });
+            return;
+        }
+
+        PcmStream::start();
+    }
+    catch (exception& e) {
+        LOG(ERROR, LOG_TAG) << "Error during Jack connection: " << e.what() << "\n";
+        stop();
+    }
+}
+
+
+bool JackStream::openJackConnection()
+{
+    client_ = jack_client_open(name_.c_str(), JackNoStartServer, &status_, nullptr);
+
+    if (client_ == NULL) {
+        return false;
+    }
+
+    LOG(INFO, LOG_TAG) << "Connected Jack client " << jack_get_client_name(client_) << "\n";
+
+    jack_nframes_t jack_sample_rate = jack_get_sample_rate(client_);
+    if (jack_sample_rate != sampleFormat_.rate()) {
+        throw SnapException(
+            "Jack streams must match the sample rate of the Jack server. "
+            "The server sample rate is " + cpt::to_string(jack_sample_rate) + "."
+        );
+    }
+
+    jack_time_t connect_time = jack_get_time();
+    jackConnectTime_ = std::chrono::steady_clock::now();
+    jackTimeAdjust_ = chrono::duration_cast<chrono::microseconds>(
+        jackConnectTime_.time_since_epoch()
+    ).count() - connect_time;
+
+    LOG(DEBUG, LOG_TAG) << name_ << ": Jack server time adjustment is "
+        << jackTimeAdjust_ << "\n";
+
+    jack_set_process_callback(client_, processCallback, this);
+    jack_on_shutdown(client_, jackShutdown, this);
+    jack_set_port_registration_callback(client_, jackPortRegistration, this);
+
+    int err = jack_activate(client_);
+    if (err)
+    {
+        LOG(ERROR, LOG_TAG) << "Failed to activate Jack client "
+            << name_ << ": " << err << "\n";
+        closeJackConnection();
+        return false;
+    }
+
+    return true;
+}
+
+bool JackStream::createJackPorts()
+{
+    if (ports_.size() > 0) {
+        throw SnapException("Jack ports already created!");
+    }
+
+    int channelCount = sampleFormat_.channels();
+    ports_.reserve(channelCount);
+
+    // Register input ports
+    for (int i=0; i < channelCount; ++i)
+    {
+        std::string portName = "input_" + std::to_string(i);
+        jack_port_t *port = jack_port_register(client_, portName.c_str(),
+                JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
+        if (port == NULL)
+        {
+            LOG(ERROR, LOG_TAG) << name_ << ": failed to register port " << portName << "\n";
+            return false;
+        }
+        ports_.push_back(port);
+    }
+
+    return true;
+}
+
+/**
+ * Reads the Jack port buffers, interlaces and converts the samples
+ * to the stream format and adds the resulting data to the
+ * ringbuffer, along with the jack timing information.
+ */
+int JackStream::readJackBuffers(jack_nframes_t nframes)
+{
+    jack_nframes_t current_frames;
+    jack_time_t current_usecs;
+    jack_time_t next_usecs;
+    float period_usecs;
+
+    int err = jack_get_cycle_times(client_, &current_frames, &current_usecs,
+            &next_usecs, &period_usecs);
+    if (err)
+    {
+        LOG(ERROR, LOG_TAG) << "Unable to get Jack cycle times: " << err << "\n";
+        return -1;
+    }
+
+    int bytes_per_frame = sampleFormat_.sampleSize();
+    int num_channels = sampleFormat_.channels();
+    int payload_skip = bytes_per_frame * num_channels;
+
+    // resize chunk payload buffer to match the Jack buffer size, if required
+    if (chunk_->getFrameCount() != nframes)
+    {
+        LOG(TRACE, LOG_TAG) << "Resizing chunk to " << nframes << " frames\n";
+        chunk_->setFrameCount(nframes);
+        silent_chunk_ = std::vector<char>(chunk_->payloadSize, 0);
+    }
+
+    int connectedPorts = 0;
+
+    for (size_t i=0; i < ports_.size(); i++)
+    {
+        int payload_offset = bytes_per_frame * i;
+        jack_port_t *port = ports_[i];
+
+        if (jack_port_connected(port))
+        {
+            connectedPorts++;
+        }
+
+        jack_default_audio_sample_t *buf = static_cast<jack_default_audio_sample_t *>(
+            jack_port_get_buffer(port, nframes)
+        );
+
+        if (buf == NULL)
+        {
+            LOG(ERROR, LOG_TAG) << "Unable to get Jack port buffer!\n";
+            return -1;
+        }
+
+        interleave_func_(chunk_->payload + payload_offset, buf, nframes, payload_skip);
+    }
+
+    if (connectedPorts == 0 || isSilent(*chunk_))
+    {
+        silence_ += chunk_->duration<std::chrono::microseconds>();
+        if (silence_ > idle_threshold_)
+        {
+            setState(ReaderState::kIdle);
+        }
+    }
+    else
+    {
+        silence_ = 0ms;
+        setState(ReaderState::kPlaying);
+    }
+
+    if ((state_ == ReaderState::kPlaying) || ((state_ == ReaderState::kIdle) && send_silence_))
+    {
+        // We use the (adjusted) Jack server time as chunk time, that way all Jack
+        // streams will play simultaneously (hopefully!)
+        tvEncodedChunk_ = std::chrono::time_point<std::chrono::steady_clock>(
+            static_cast<chrono::microseconds>(current_usecs + jackTimeAdjust_)
+        );
+
+        // TODO: should we chunkRead() in a separate thread?
+        chunkRead(*chunk_);
+    }
+
+    return 0;
+}
+
+void JackStream::closeJackConnection()
+{
+    if (client_ == NULL) {
+        return;
+    }
+
+    LOG(INFO, LOG_TAG) << "Closing Jack connection for " << name_ << "\n";
+
+    ports_.clear();
+
+    jack_client_close(client_);
+    client_ = NULL;
+}
+
+void JackStream::onJackPortRegistration(jack_port_id_t port_id, int registered)
+{
+    if (!doAutoConnect_ || !registered) {
+        return;
+    }
+
+    jack_port_t *port = jack_port_by_id(client_, port_id);
+    if (port == NULL) {
+        return;
+    }
+
+    if (jack_port_is_mine(client_, port)) {
+        return;
+    }
+
+    boost::asio::post(strand_, [this] { autoConnectPorts(); });
+}
+
+void JackStream::autoConnectPorts()
+{
+    const char **portNames = jack_get_ports(client_, autoConnectRegex_.c_str(),
+            NULL, JackPortIsOutput);
+
+    if (portNames == NULL) {
+        return;
+    }
+
+    size_t portIdx = 0;
+    int nameIdx = 0;
+
+    while(portIdx < ports_.size() && portNames[nameIdx] != NULL)
+    {
+        if (nameIdx < autoConnectSkip_)
+        {
+            nameIdx++;
+            continue;
+        }
+
+        if (!jack_port_connected_to(ports_[portIdx], portNames[nameIdx])) {
+
+            const char *localPortName = jack_port_name(ports_[portIdx]);
+            int err = jack_connect(client_, portNames[nameIdx], localPortName);
+            if (err != 0) {
+                LOG(ERROR, LOG_TAG) << "Unable to autoconnect " << localPortName
+                    << " to " << portNames[nameIdx] << "(Error: " << err << ")\n";
+            }
+        }
+        portIdx++;
+        nameIdx++;
+    }
+
+    jack_free(portNames);
+}
+
+void JackStream::onJackShutdown()
+{
+    LOG(ERROR, LOG_TAG) << "Jack has shut down, trying to connect again!\n";
+    PcmStream::stop();
+    ports_.clear();
+    client_ = NULL;
+    wait(read_timer_, 1000ms, [this] { tryConnect(); });
+}
+
+int JackStream::processCallback(jack_nframes_t nframes, void* arg)
+{
+    return static_cast<JackStream *>(arg)->readJackBuffers(nframes);
+}
+
+void JackStream::jackShutdown(void* arg)
+{
+    static_cast<JackStream *>(arg)->onJackShutdown();
+}
+
+void JackStream::jackErrorMessage(const char* msg)
+{
+    //LOG(TRACE, LOG_TAG) << "Jack Error: " << msg << "\n";
+}
+
+void JackStream::jackInfoMessage(const char* msg)
+{
+    //LOG(TRACE, LOG_TAG) << msg << "\n";
+}
+
+void JackStream::jackPortRegistration(jack_port_id_t port_id, int registered, void* arg)
+{
+    return static_cast<JackStream *>(arg)->onJackPortRegistration(port_id, registered);
+}
+
+} // namespace streamreader
+

server/streamreader/jack_stream.hpp

@@ -0,0 +1,98 @@
+/***
+    This file is part of snapcast
+    Copyright (C) 2014-2024  Johannes Pohl
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#pragma once
+
+#include <jack/jack.h>
+
+// local headers
+#include "pcm_stream.hpp"
+#include <server/server_settings.hpp>
+
+// 3rd party headers
+#include <boost/asio/spawn.hpp>
+#include <boost/asio/io_context.hpp>
+#include <boost/asio/steady_timer.hpp>
+
+
+namespace streamreader
+{
+
+
+/// Reads and decodes PCM data from a Jack server
+/**
+ * Reads PCM from a Jack server and passes the data to an encoder.
+ * Implements EncoderListener to get the encoded data.
+ * Data is passed to the PcmStream::Listener
+ */
+class JackStream : public PcmStream
+{
+public:
+    /// ctor. Encoded PCM data is passed to the PipeListener
+    JackStream(PcmStream::Listener* pcmListener, boost::asio::io_context& ioc, const ServerSettings& server_settings, const StreamUri& uri);
+
+    void start() override;
+    void stop() override;
+
+protected:
+    bool openJackConnection();
+    void closeJackConnection();
+    bool createJackPorts();
+    void tryConnect();
+    int readJackBuffers(jack_nframes_t nframes);
+
+    void onJackPortRegistration(jack_port_id_t port_id, int registered);
+    void onJackShutdown();
+
+    void autoConnectPorts();
+
+    jack_client_t *client_;
+    jack_status_t status_;
+    std::vector<jack_port_t *> ports_;
+    jack_nframes_t jackConnectFrames_;
+    std::chrono::time_point<std::chrono::steady_clock> jackConnectTime_;
+    jack_time_t jackTimeAdjust_;
+    SampleFormat jackSampleFormat_;
+
+    std::string autoConnectRegex_;
+    bool doAutoConnect_ = false;
+    int autoConnectSkip_;
+
+    void (*interleave_func_)(char *, jack_default_audio_sample_t *, unsigned long, unsigned long);
+
+    bool first_;
+    std::chrono::time_point<std::chrono::steady_clock> nextTick_;
+    boost::asio::steady_timer read_timer_;
+    std::chrono::microseconds silence_;
+    std::string lastException_;
+
+    /// send silent chunks to clients
+    bool send_silence_;
+    /// silence duration before switching the stream to idle
+    std::chrono::milliseconds idle_threshold_;
+
+    static int processCallback(jack_nframes_t nframes, void* arg);
+    static void jackShutdown(void* arg);
+    static void jackErrorMessage(const char* msg);
+    static void jackInfoMessage(const char* msg);
+    static void jackPortConnect(jack_port_id_t a, jack_port_id_t b, int connect, void* arg);
+    static void jackPortRegistration(jack_port_id_t port_id, int registered, void* arg);
+};
+
+} // namespace streamreader
+

server/streamreader/stream_manager.cpp

@@ -24,6 +24,9 @@
 #ifdef HAS_ALSA
 #include "alsa_stream.hpp"
 #endif
+#ifdef HAS_JACK
+#include "jack_stream.hpp"
+#endif
 #include "common/snap_exception.hpp"
 #include "common/str_compat.hpp"
 #include "file_stream.hpp"
@@ -101,6 +104,12 @@ PcmStreamPtr StreamManager::addStream(StreamUri& streamUri)
     {
         stream = make_shared<AlsaStream>(listener, io_context_, settings_, streamUri);
     }
+#endif
+#ifdef HAS_JACK
+    else if (streamUri.scheme == "jack")
+    {
+        stream = make_shared<JackStream>(listener, io_context_, settings_, streamUri);
+    }
 #endif
     else if ((streamUri.scheme == "spotify") || (streamUri.scheme == "librespot"))
     {