Add InputBuffered

1 files changed, 131 insertions, 0 deletions

diff --git a/src/inputs/InputBuffered.cpp b/src/inputs/InputBuffered.cpp
new file mode 100644
index 0000000..9eea2a7
--- /dev/null
+++ b/src/inputs/InputBuffered.cpp
@@ -0,0 +1,131 @@
+/*
+   Copyright (C) 2009 Her Majesty the Queen in Right of Canada (Communications
+   Research Center Canada)
+
+   Copyright (C) 2013 Matthias P. Braendli
+   http://mpb.li
+
+   Base class for buffered inputs
+
+   */
+/*
+   This file is part of CRC-DabMux.
+
+   CRC-DabMux 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.
+
+   CRC-DabMux 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 CRC-DabMux.  If not, see <http://www.gnu.org/licenses/>.
+   */
+
+#include "inputs/Input.h"
+
+
+#include "TcpLog.h"
+
+#include <string>
+#include <cstring>
+#include <cstdlib>
+#include <cstdio>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+
+#ifndef _WIN32
+#   define O_BINARY 0
+#endif
+
+extern TcpLog etiLog;
+
+int InputBuffered::ReadFrame(void* buffer, int size)
+{
+    int retval = 0;
+    bool rc;
+
+    switch (m_bufferstate) {
+        case PREBUFFERING:
+            rc = FillBuffer();
+            if (rc) {
+                m_prebuffer_count--;
+            }
+            if (m_prebuffer_count == 0) {
+                etiLog.print(TcpLog::NOTICE, "input %s: pre-buffering complete\n",
+                        GetName());
+                m_bufferstate = RUNNING;
+            }
+            break;
+
+        case RUNNING:
+            rc = FillBuffer();
+            if (m_buffer.empty()) {
+                etiLog.print(TcpLog::WARNING,
+                        "input %s input empty, re-enabling pre-buffering\n",
+                        GetName());
+
+                // reinitialise prebuffering
+                m_bufferstate = PREBUFFERING;
+                m_prebuffer_count = m_prebuffer_stages;
+            }
+            else {
+                std::vector<char> &buffer_head = m_buffer.front();
+
+                memcpy(buffer, &buffer_head.front(), size);
+                etiLog.print(TcpLog::NOTICE,
+                        "input %s got %d, %d\n",
+                        GetName(), rc, m_buffer.size());
+
+                m_buffer.pop_front();
+                retval = size;
+            }
+            break;
+    }
+
+    // If we haven't filled buffer, return a nulled one
+    if (retval == 0) {
+        memset(buffer, 0, size);
+        retval = size;
+    }
+
+    return retval;
+}
+
+// This implemenation of FillBuffer assumes that
+// input and output frames have same size.
+// That's not the case with DAB+ superframes
+bool InputBuffered::FillBuffer()
+{
+    if (m_buffer.size() > m_overfull_thresh) {
+        etiLog.print(TcpLog::WARNING,
+                "input %s buffer full, dropping frame !\n",
+                GetName());
+
+        // drop the surplus
+        int num_frames_to_drop = m_buffer.size() - m_overfull_thresh;
+        while (num_frames_to_drop--)
+            m_buffer.pop_front();
+
+        return true;
+    }
+    else {
+        // copy the input frame into the frame_buffer one to one
+        std::vector<char> frame(m_source_size);
+        int rc = ReadSource(&frame.front(), m_source_size);
+        if (rc == m_source_size)
+        {
+            m_buffer.push_back(frame);
+            return true;
+        }
+        else
+        {
+            return false;
+        }
+    }
+}
+