Make ZMQ prebuffering configurable

2 files changed, 37 insertions, 12 deletions

diff --git a/src/dabInputZmq.cpp b/src/dabInputZmq.cpp
index ffe1e6b..1106fee 100644
--- a/src/dabInputZmq.cpp
+++ b/src/dabInputZmq.cpp
@@ -125,7 +125,7 @@ int DabInputZmqBase::readFrame(void* buffer, int size)
          * filled to the prebuffering length.
          */
         if (m_frame_buffer.size() >= 1.5*m_frame_buffer_limit) {
-            size_t over_max = m_frame_buffer.size() - INPUT_ZMQ_PREBUFFERING;
+            size_t over_max = m_frame_buffer.size() - m_prebuffering;
 
             while (over_max--) {
                 m_frame_buffer.pop_front();
@@ -154,10 +154,10 @@ int DabInputZmqBase::readFrame(void* buffer, int size)
         }
     }
 
-    if (m_prebuffering > 0) {
+    if (m_prebuf_current > 0) {
         if (rc > 0)
-            m_prebuffering--;
-        if (m_prebuffering == 0)
+            m_prebuf_current--;
+        if (m_prebuf_current == 0)
             etiLog.log(info, "inputZMQ %s input pre-buffering complete\n",
                 m_name.c_str());
 
@@ -174,7 +174,7 @@ int DabInputZmqBase::readFrame(void* buffer, int size)
         etiLog.log(warn, "inputZMQ %s input empty, re-enabling pre-buffering\n",
                 m_name.c_str());
         // reset prebuffering
-        m_prebuffering = INPUT_ZMQ_PREBUFFERING;
+        m_prebuf_current = m_prebuffering;
 
         /* We have no data to give, we give a zeroed frame */
         global_stats->notifyUnderrun(m_name);
@@ -329,6 +329,20 @@ void DabInputZmqBase::set_parameter(const string& parameter,
 
         m_frame_buffer_limit = new_limit;
     }
+    else if (parameter == "prebuffering") {
+        size_t new_prebuf = atol(value.c_str());
+
+        if (new_prebuf < INPUT_ZMQ_MIN_BUFFER_SIZE) {
+            throw ParameterError("Desired prebuffering too small."
+                   " Minimum " STRINGIFY(INPUT_ZMQ_MIN_BUFFER_SIZE) );
+        }
+        else if (new_prebuf > INPUT_ZMQ_MAX_BUFFER_SIZE) {
+            throw ParameterError("Desired prebuffering too large."
+                   " Maximum " STRINGIFY(INPUT_ZMQ_MAX_BUFFER_SIZE) );
+        }
+
+        m_prebuffering = new_prebuf;
+    }
     else if (parameter == "enable") {
         if (value == "1") {
             m_enable_input = true;
@@ -354,6 +368,9 @@ const string DabInputZmqBase::get_parameter(const string& parameter) const
     if (parameter == "buffer") {
         ss << m_frame_buffer_limit;
     }
+    else if (parameter == "prebuffering") {
+        ss << m_prebuffering;
+    }
     else if (parameter == "enable") {
         if (m_enable_input)
             ss << "true";
diff --git a/src/dabInputZmq.h b/src/dabInputZmq.h
index 9f7fba2..11fb49a 100644
--- a/src/dabInputZmq.h
+++ b/src/dabInputZmq.h
@@ -59,7 +59,7 @@
  */
 
 // Number of elements to prebuffer before starting the pipeline
-#define INPUT_ZMQ_PREBUFFERING (5*4) // 480ms
+#define INPUT_ZMQ_DEF_PREBUFFERING (5*4) // 480ms
 
 // Default frame_buffer size in number of elements
 #define INPUT_ZMQ_DEF_BUFFER_SIZE (5*8) // 960ms
@@ -80,9 +80,12 @@ class DabInputZmqBase : public DabInputBase, public RemoteControllable {
             : RemoteControllable(name),
             m_zmq_context(1),
             m_zmq_sock(m_zmq_context, ZMQ_SUB),
-            m_bitrate(0), m_prebuffering(INPUT_ZMQ_PREBUFFERING),
+            m_bitrate(0), m_prebuffering(INPUT_ZMQ_DEF_PREBUFFERING),
             m_enable_input(true),
-            m_frame_buffer_limit(INPUT_ZMQ_DEF_BUFFER_SIZE) { }
+            m_frame_buffer_limit(INPUT_ZMQ_DEF_BUFFER_SIZE) {
+                RC_ADD_PARAMETER(enable,
+                        "If the input is enabled. Set to zero to empty the buffer.");
+            }
 
         virtual int open(const std::string inputUri);
         virtual int readFrame(void* buffer, int size);
@@ -109,6 +112,9 @@ class DabInputZmqBase : public DabInputBase, public RemoteControllable {
 
         size_t m_frame_buffer_limit;
         std::list<char*> m_frame_buffer; //stores elements of type char[<framesize>]
+
+    private:
+        int m_prebuf_current;
 };
 
 class DabInputZmqMPEG : public DabInputZmqBase {
@@ -117,8 +123,9 @@ class DabInputZmqMPEG : public DabInputZmqBase {
             : DabInputZmqBase(name) {
                 RC_ADD_PARAMETER(buffer,
                         "Size of the input buffer [mpeg frames]");
-                RC_ADD_PARAMETER(enable,
-                        "If the input is enabled. Set to zero to empty the buffer.");
+
+                RC_ADD_PARAMETER(prebuffering,
+                        "Min buffer level before streaming starts [mpeg frames]");
             }
 
     private:
@@ -131,8 +138,9 @@ class DabInputZmqAAC : public DabInputZmqBase {
             : DabInputZmqBase(name) {
                 RC_ADD_PARAMETER(buffer,
                         "Size of the input buffer [aac superframes]");
-                RC_ADD_PARAMETER(enable,
-                        "If the input is enabled. Set to zero to empty the buffer.");
+
+                RC_ADD_PARAMETER(prebuffering,
+                        "Min buffer level before streaming starts [aac superframes]");
             }
 
     private: