Add a proper bypass for the jitter buffer if wanted.

2025-12-21 15:09:23 +08:00 · 2018-02-05 19:46:27 +00:00
parent 14a06e7182
commit 4323c02a0a
16 changed files with 287 additions and 53 deletions
--- a/DelayBuffer.cpp
+++ b/DelayBuffer.cpp
@@ -0,0 +1,137 @@
+/*
+*   Copyright (C) 2018 by Jonathan Naylor G4KLX
+*
+*   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 2 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, write to the Free Software
+*   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "DelayBuffer.h"
+
+#include "Log.h"
+
+#include <cstdio>
+#include <cassert>
+#include <cstring>
+
+CDelayBuffer::CDelayBuffer(const std::string& name, unsigned int blockSize, unsigned int blockTime, unsigned int jitterTime, bool debug) :
+m_name(name),
+m_blockSize(blockSize),
+m_blockTime(blockTime),
+m_debug(debug),
+m_timer(1000U, 0U, jitterTime),
+m_stopWatch(),
+m_running(false),
+m_buffer(1000U, name.c_str()),
+m_outputCount(0U),
+m_lastData(NULL),
+m_lastDataLength(0U)
+{
+	assert(blockSize > 0U);
+	assert(blockTime > 0U);
+	assert(jitterTime > 0U);
+
+	m_lastData = new unsigned char[m_blockSize];
+
+	reset();
+}
+
+CDelayBuffer::~CDelayBuffer()
+{
+	delete[] m_lastData;
+}
+
+bool CDelayBuffer::addData(const unsigned char* data, unsigned int length)
+{
+	assert(data != NULL);
+	assert(length > 0U);
+	assert(length == m_blockSize);
+
+	if (m_debug)
+		LogDebug("%s, DelayBuffer: appending data", m_name.c_str());
+
+	m_buffer.addData(data, length);
+
+	if (!m_timer.isRunning()) {
+		LogDebug("%s, DelayBuffer: starting the timer from append", m_name.c_str());
+		m_timer.start();
+	}
+
+	return true;
+}
+
+B_STATUS CDelayBuffer::getData(unsigned char* data, unsigned int& length)
+{
+	assert(data != NULL);
+
+	if (!m_running)
+		return BS_NO_DATA;
+
+	unsigned int needed = m_stopWatch.elapsed() / m_blockTime + 2U;
+	if (needed <= m_outputCount)
+		return BS_NO_DATA;
+
+	if (!m_buffer.isEmpty()) {
+		if (m_debug)
+			LogDebug("%s, DelayBuffer: returning data, elapsed=%ums", m_name.c_str(), m_stopWatch.elapsed());
+
+		length = m_buffer.getData(data, m_blockSize);
+
+		// Save this data in case no more data is available next time
+		::memcpy(m_lastData, data, length);
+		m_lastDataLength = length;
+
+		m_outputCount++;
+
+		return BS_DATA;
+	}
+
+	LogDebug("%s, DelayBuffer: no data available, elapsed=%ums", m_name.c_str(), m_stopWatch.elapsed());
+
+	// Return the last data frame if we have it
+	if (m_lastDataLength > 0U) {
+		LogDebug("%s, DelayBuffer: returning the last received frame", m_name.c_str());
+		::memcpy(data, m_lastData, m_lastDataLength);
+		length = m_lastDataLength;
+
+		m_outputCount++;
+
+		return BS_MISSING;
+	}
+
+	return BS_NO_DATA;
+}
+
+void CDelayBuffer::reset()
+{
+	m_buffer.clear();
+
+	m_lastDataLength = 0U;
+
+	m_outputCount = 0U;
+
+	m_timer.stop();
+
+	m_running = false;
+}
+
+void CDelayBuffer::clock(unsigned int ms)
+{
+	m_timer.clock(ms);
+	if (m_timer.isRunning() && m_timer.hasExpired()) {
+		if (!m_running) {
+			m_stopWatch.start();
+			m_running = true;
+		}
+	}
+}