Add JACK input support

1 files changed, 139 insertions, 0 deletions

diff --git a/src/JackInput.cpp b/src/JackInput.cpp
new file mode 100644
index 0000000..f39bf14
--- /dev/null
+++ b/src/JackInput.cpp
@@ -0,0 +1,139 @@
+/* ------------------------------------------------------------------
+ * Copyright (C) 2011 Martin Storsjo
+ * Copyright (C) 2013,2014 Matthias P. Braendli
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ * -------------------------------------------------------------------
+ */
+
+#include <cstdio>
+#include <string>
+#include "config.h"
+
+#if HAVE_JACK
+
+extern "C" {
+#include <jack/jack.h>
+}
+
+#include "JackInput.h"
+#include <sys/time.h>
+
+using namespace std;
+
+int JackInput::prepare()
+{
+    jack_options_t options = JackNullOption;
+    jack_status_t status;
+    const char *server_name = NULL;
+
+    m_client = jack_client_open(m_jack_name.c_str(), options, &status, server_name);
+    if (m_client == NULL) {
+        fprintf(stderr, "jack_client_open() failed, "
+                "status = 0x%2.0x\n", status);
+        if (status & JackServerFailed) {
+            fprintf(stderr, "Unable to connect to JACK server\n");
+        }
+        return -1;
+    }
+
+    if (status & JackServerStarted) {
+        fprintf(stderr, "JACK server started\n");
+    }
+
+    if (status & JackNameNotUnique) {
+        fprintf(stderr, "JACK name '%s' not unique!\n", m_jack_name.c_str());
+        return -1;
+    }
+
+    /* Set up real-time process callback */
+    jack_set_process_callback(m_client, process_cb, this);
+
+    /* tell the JACK server to call `shutdown_cb' if
+       it ever shuts down, either entirely, or if it
+       just decides to stop calling us. */
+    jack_on_shutdown(m_client, shutdown_cb, this);
+
+    if (m_rate != jack_get_sample_rate(m_client)) {
+        fprintf(stderr, "JACK uses different sample_rate %d "
+                "than requested (%d)!\n",
+                jack_get_sample_rate(m_client),
+                m_rate);
+        return -1;
+    }
+
+    /* create ports */
+    for (int i = 0; i < m_channels; i++) {
+        std::stringstream port_name;
+        port_name << "input" << i;
+
+        jack_port_t* input_port = jack_port_register(m_client,
+                port_name.str().c_str(),
+                JACK_DEFAULT_AUDIO_TYPE,
+                JackPortIsInput,
+                0);
+
+        if (input_port == NULL) {
+            fprintf(stderr, "no more JACK ports available\n");
+            return -1;
+        }
+
+        m_input_ports.push_back(input_port);
+    }
+
+    /* Tell the JACK server that we are ready to roll. Our
+     * process() callback will start running now. */
+    if (jack_activate(m_client)) {
+        fprintf (stderr, "JACK: cannot activate client");
+        return -1;
+    }
+}
+
+void JackInput::jack_process(jack_nframes_t nframes)
+{
+    // Convert samples to shorts
+    std::vector<int16_t> buffer(m_channels * nframes);
+
+    for (int chan = 0; chan < m_channels; chan++) {
+        // start offset interleaving
+        int i = chan;
+
+        const int dst_skip = m_channels;
+
+        jack_default_audio_sample_t* src =
+            (jack_default_audio_sample_t*)jack_port_get_buffer(m_input_ports[chan], nframes);
+
+        jack_nframes_t n = nframes;
+        while (n--) {
+            if (*src <= -1.0f) {
+                buffer[i] = 32767;
+            }
+            else if (*src >= 1.0f) {
+                buffer[i] = -32768;
+            }
+            else {
+                buffer[i] =
+                    (int16_t)lrintf(*src * 32768.0f);
+            }
+
+            i += dst_skip;
+            src++;
+        }
+    }
+
+    m_queue.push((uint8_t*)&buffer.front(), buffer.size() * sizeof(uint16_t));
+}
+
+#endif // HAVE_JACK
+