39 [WIP] - restructured the polyphase filter process. Previous version

was not computationally feasible with my 3rd Gen i7 processor running and airspy at 10 MHz. Restructured the polyphase channelizer to use vector iteration structures that the JDK 9 JIT compiler can translate into SIMD instructions. Separated the IFFT processing from the filter process so that they can be executed on separate threads and this allows the processing to occur real time. P25 C4FM decoding at 25 kHz channel sample rate using an airspy 10MHz sample stream seems to be working nicely with ~25% CPU usage and ~300 to 500 MB memory usage. Incremental (parallel) channel decoding should have a minimal increase in CPU loading since all of the 12.5 kHz channels are available in the polyphase channelizer and the only additional workload is the decoding of the 25 kHz sample stream. There is still an issue with stopping channels and the channelizer keeps processing, and occasionally when starting traffic channels something deadlocks and causes out of memory.
2026-11-12 08:37:25 -05:00 · 2018-04-15 09:05:06 -04:00
parent ff9395e4b9
commit e971ad4582
18 changed files with 637 additions and 702 deletions
--- a/src/main/java/io/github/dsheirer/sample/buffer/ReusableChannelResultsBufferQueue.java
+++ b/src/main/java/io/github/dsheirer/sample/buffer/ReusableChannelResultsBufferQueue.java
@@ -0,0 +1,55 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 Dennis Sheirer
+ *
+ * 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/>
+ *
+ ******************************************************************************/
+package io.github.dsheirer.sample.buffer;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ReusableChannelResultsBufferQueue extends AbstractReusableBufferQueue<ReusableChannelResultsBuffer>
+{
+    private final static Logger mLog = LoggerFactory.getLogger(ReusableChannelResultsBufferQueue.class);
+
+    public ReusableChannelResultsBufferQueue(String debugName)
+    {
+        super(debugName);
+    }
+
+    public ReusableChannelResultsBufferQueue()
+    {
+    }
+
+    /**
+     * Returns a reusable buffer from an internal recycling queue, or creates a new buffer if there are currently no
+     * buffers available for reuse.
+     *
+     * @return a reusable buffer
+     */
+    public ReusableChannelResultsBuffer getBuffer()
+    {
+        ReusableChannelResultsBuffer buffer = getRecycledBuffer();
+
+        if(buffer == null)
+        {
+            buffer = new ReusableChannelResultsBuffer(this);
+            incrementBufferCount();
+
+            buffer.setDebugName("Owner:" + getDebugName());
+            mLog.debug("Buffer Created - Count:" + getBufferCount() + (getDebugName() != null ? " [" + getDebugName() + "]" : ""));
+        }
+
+        return buffer;
+    }
+}