Merge branch 'max_queue_size'

db/zm_create.sql.in

@@ -497,11 +497,12 @@ CREATE TABLE `Monitors` (
   `LabelX` smallint(5) unsigned NOT NULL default '0',
   `LabelY` smallint(5) unsigned NOT NULL default '0',
   `LabelSize` smallint(5) unsigned NOT NULL DEFAULT '1',
-  `ImageBufferCount` smallint(5) unsigned NOT NULL default '100',
+  `ImageBufferCount` smallint(5) unsigned NOT NULL default '3',
-  `WarmupCount` smallint(5) unsigned NOT NULL default '25',
+  `MaxImageBufferCount` smallint(5) unsigned NOT NULL default '0',
+  `WarmupCount` smallint(5) unsigned NOT NULL default '0',
   `PreEventCount` smallint(5) unsigned NOT NULL default '10',
   `PostEventCount` smallint(5) unsigned NOT NULL default '10',
-  `StreamReplayBuffer` int(10) unsigned NOT NULL default '1000',
+  `StreamReplayBuffer` int(10) unsigned NOT NULL default '0',
   `AlarmFrameCount` smallint(5) unsigned NOT NULL default '1',
   `SectionLength` int(10) unsigned NOT NULL default '600',
   `MinSectionLength` int(10) unsigned NOT NULL default '10',

db/zm_update-1.35.22.sql

@@ -0,0 +1,19 @@
+--
+-- Add MaxImageBufferCount, set it to ImageBufferCount if that was large and set ImageBufferCount to 3
+--
+
+SET @s = (SELECT IF(
+    (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE table_schema = DATABASE()
+     AND table_name = 'Monitors'
+     AND column_name = 'MaxImageBufferCount'
+    ) > 0,
+"SELECT 'Column MaxImageBufferCount already exists in Monitors'",
+"ALTER TABLE `Monitors` ADD `MaxImageBufferCount` smallint(5) unsigned NOT NULL default '0' AFTER `ImageBufferCount`"
+));
+
+PREPARE stmt FROM @s;
+EXECUTE stmt;
+
+UPDATE `Monitors` SET MaxImageBufferCount=ImageBufferCount WHERE ImageBufferCount >= 20;
+UPDATE `Monitors` SET ImageBufferCount = 3;
+

distros/redhat/zoneminder.spec

@@ -28,7 +28,7 @@
 %global _hardened_build 1
 
 Name: zoneminder
-Version: 1.35.21
+Version: 1.35.22
 Release: 1%{?dist}
 Summary: A camera monitoring and analysis tool
 Group: System Environment/Daemons

src/zm_monitor.cpp

@@ -85,7 +85,7 @@ std::string load_monitor_sql =
 "`RecordAudio`, "
 "`Brightness`, `Contrast`, `Hue`, `Colour`, "
 "`EventPrefix`, `LabelFormat`, `LabelX`, `LabelY`, `LabelSize`,"
-"`ImageBufferCount`, `WarmupCount`, `PreEventCount`, `PostEventCount`, `StreamReplayBuffer`, `AlarmFrameCount`, "
+"`ImageBufferCount`, `MaxImageBufferCount`, `WarmupCount`, `PreEventCount`, `PostEventCount`, `StreamReplayBuffer`, `AlarmFrameCount`, "
 "`SectionLength`, `MinSectionLength`, `FrameSkip`, `MotionFrameSkip`, "
 "`FPSReportInterval`, `RefBlendPerc`, `AlarmRefBlendPerc`, `TrackMotion`, `Exif`,"
 "`RTSPServer`, `RTSPStreamName`,"
@@ -327,6 +327,7 @@ Monitor::Monitor()
   label_coord(Coord(0,0)),
   label_size(0),
   image_buffer_count(0),
+  max_image_buffer_count(0),
   warmup_count(0),
   pre_event_count(0),
   post_event_count(0),
@@ -431,7 +432,7 @@ Monitor::Monitor()
  "RecordAudio, "
  "Brightness, Contrast, Hue, Colour, "
  "EventPrefix, LabelFormat, LabelX, LabelY, LabelSize,"
- "ImageBufferCount, WarmupCount, PreEventCount, PostEventCount, StreamReplayBuffer, AlarmFrameCount, "
+ "ImageBufferCount, `MaxImageBufferCount`, WarmupCount, PreEventCount, PostEventCount, StreamReplayBuffer, AlarmFrameCount, "
  "SectionLength, MinSectionLength, FrameSkip, MotionFrameSkip, "
  "FPSReportInterval, RefBlendPerc, AlarmRefBlendPerc, TrackMotion, Exif,"
  "`RTSPServer`,`RTSPStreamName`,
@@ -579,10 +580,14 @@ void Monitor::Load(MYSQL_ROW dbrow, bool load_zones=true, Purpose p = QUERY) {
   label_size = atoi(dbrow[col]); col++;
 
   image_buffer_count = atoi(dbrow[col]); col++;
+  max_image_buffer_count = atoi(dbrow[col]); col++;
   warmup_count = atoi(dbrow[col]); col++;
   pre_event_count = atoi(dbrow[col]); col++;
-  packetqueue.setMaxVideoPackets(pre_event_count);
+  packetqueue.setPreEventVideoPackets(pre_event_count);
+  packetqueue.setMaxVideoPackets(max_image_buffer_count);
+
   packetqueue.setKeepKeyframes(videowriter == PASSTHROUGH);
+
   post_event_count = atoi(dbrow[col]); col++;
   stream_replay_buffer = atoi(dbrow[col]); col++;
   alarm_frame_count = atoi(dbrow[col]); col++;
@@ -590,7 +595,6 @@ void Monitor::Load(MYSQL_ROW dbrow, bool load_zones=true, Purpose p = QUERY) {
     alarm_frame_count = 1;
   else if ( alarm_frame_count > MAX_PRE_ALARM_FRAMES )
     alarm_frame_count = MAX_PRE_ALARM_FRAMES;
-  pre_event_buffer_count = pre_event_count + alarm_frame_count + warmup_count - 1;
 
   section_length = atoi(dbrow[col]); col++;
   min_section_length = atoi(dbrow[col]); col++;
@@ -639,9 +643,9 @@ void Monitor::Load(MYSQL_ROW dbrow, bool load_zones=true, Purpose p = QUERY) {
 
   // Should maybe store this for later use
   std::string monitor_dir = stringtf("%s/%d", storage->Path(), id);
-  LoadCamera();
 
   if ( purpose != QUERY ) {
+    LoadCamera();
     Zone **zones = 0;
     int n_zones = Zone::Load(this, zones);
     this->AddZones(n_zones, zones);
@@ -676,7 +680,6 @@ void Monitor::Load(MYSQL_ROW dbrow, bool load_zones=true, Purpose p = QUERY) {
     }
   }  // end if purpose
 
-
   Debug(1, "Loaded monitor %d(%s), %d zones", id, name, n_zones);
 } // Monitor::Load
 
@@ -3125,7 +3128,7 @@ int Monitor::PrimeCapture() {
     }
 
     Debug(2, "Video stream id is %d, audio is %d, minimum_packets to keep in buffer %d",
-        video_stream_id, audio_stream_id, pre_event_buffer_count);
+        video_stream_id, audio_stream_id, pre_event_count);
 
     if (rtsp_server) {
       if (video_stream_id >= 0) {

src/zm_monitor.h

@@ -292,10 +292,9 @@ protected:
   char       label_format[64];    // The format of the timestamp on the images
   Coord      label_coord;      // The coordinates of the timestamp on the images
   int        label_size;         // Size of the timestamp on the images
-  int32_t   image_buffer_count;   // Size of circular image buffer, at least twice the size of the pre_event_count
+  int32_t    image_buffer_count;        // Size of circular image buffer, kept in /dev/shm
-  int        pre_event_buffer_count;   // Size of dedicated circular pre event buffer used when analysis is not performed at capturing framerate,
+  int32_t    max_image_buffer_count;    // Max # of video packets to keep in packet queue
-  // value is pre_event_count + alarm_frame_count - 1
+  int        warmup_count;              // How many images to process before looking for events
-  int        warmup_count;      // How many images to process before looking for events
   int        pre_event_count;    // How many images to hold and prepend to an alarm event
   int        post_event_count;    // How many unalarmed images must occur before the alarm state is reset
   int        stream_replay_buffer;   // How many frames to store to support DVR functions, IGNORED from this object, passed directly into zms now

src/zm_packetqueue.cpp

@@ -29,6 +29,7 @@
 PacketQueue::PacketQueue():
   video_stream_id(-1),
   max_video_packet_count(-1),
+  pre_event_video_packet_count(-1),
   max_stream_id(-1),
   packet_counts(nullptr),
   deleting(false),
@@ -84,26 +85,69 @@ bool PacketQueue::queuePacket(ZMPacket* add_packet) {
     Debug(4, "No video keyframe so no one needs us to queue packets.");
     return false;
   }
-  mutex.lock();
+  {
+    std::unique_lock<std::mutex> lck(mutex);
 
-	pktQueue.push_back(add_packet);
+    if (add_packet->packet.stream_index == video_stream_id) {
-  packet_counts[add_packet->packet.stream_index] += 1;
+      if ((max_video_packet_count > 0) and (packet_counts[video_stream_id] > max_video_packet_count)) {
-  Debug(2, "packet counts for %d is %d",
+        Warning("You have set the video packets in the queue to %d. The queue is full. Either Analysis is not keeping up or your camera's keyframe interval is larger than this setting. We are dropping packets.");
-      add_packet->packet.stream_index,
+        if (add_packet->keyframe) {
-      packet_counts[add_packet->packet.stream_index]);
+          // Have a new keyframe, so delete everything
+          while ((*pktQueue.begin() != add_packet) and (packet_counts[video_stream_id] > max_video_packet_count)) {
+            ZMPacket *zm_packet = *pktQueue.begin();
+            ZMLockedPacket *lp = new ZMLockedPacket(zm_packet);
+            if (!lp->trylock()) {
+              Debug(1, "Found locked packet when trying to free up video packets. Can't continue");
+              //delete lp;
+              break;
+            }
+            delete lp;
 
-  for (
+            for (
-      std::list<packetqueue_iterator *>::iterator iterators_it = iterators.begin();
+                std::list<packetqueue_iterator *>::iterator iterators_it = iterators.begin();
-      iterators_it != iterators.end();
+                iterators_it != iterators.end();
-      ++iterators_it
+                ++iterators_it
-      ) {
+                ) {
-    packetqueue_iterator *iterator_it = *iterators_it;
+              packetqueue_iterator *iterator_it = *iterators_it;
-    if ( *iterator_it == pktQueue.end() ) {
+              // Have to check each iterator and make sure it doesn't point to the packet we are about to delete
-      Debug(4, "pointing it %p to back", iterator_it);
+              if ( *(*iterator_it) == zm_packet ) {
-      --(*iterator_it);
+                Debug(1, "Bumping IT because it is at the front that we are deleting");
-    }
+                ++(*iterators_it);
-  }  // end foreach iterator
+              }
-  mutex.unlock();
+            }  // end foreach iterator
+
+            pktQueue.pop_front();
+            packet_counts[zm_packet->packet.stream_index] -= 1;
+            Debug(1, "Deleting a packet with stream index:%d image_index:%d with keyframe:%d, video frames in queue:%d max: %d, queuesize:%d",
+                zm_packet->packet.stream_index, zm_packet->image_index, zm_packet->keyframe, packet_counts[video_stream_id], max_video_packet_count, pktQueue.size());
+            delete zm_packet;
+          } // end while
+        }
+      }  // end if too many video packets
+      if ((max_video_packet_count > 0) and (packet_counts[video_stream_id] > max_video_packet_count)) {
+        Error("Unable to free up older packets.  Not queueing this video packet.");
+        return false;
+      }
+    }  // end if this packet is a video packet
+
+    pktQueue.push_back(add_packet);
+    packet_counts[add_packet->packet.stream_index] += 1;
+    Debug(2, "packet counts for %d is %d",
+        add_packet->packet.stream_index,
+        packet_counts[add_packet->packet.stream_index]);
+
+    for (
+        std::list<packetqueue_iterator *>::iterator iterators_it = iterators.begin();
+        iterators_it != iterators.end();
+        ++iterators_it
+        ) {
+      packetqueue_iterator *iterator_it = *iterators_it;
+      if ( *iterator_it == pktQueue.end() ) {
+        Debug(4, "pointing it %p to back", iterator_it);
+        --(*iterator_it);
+      }
+    }  // end foreach iterator
+  }  // end lock scope
   // We signal on every packet because someday we may analyze sound
   Debug(4, "packetqueue queuepacket, unlocked signalling");
   condition.notify_all();
@@ -126,13 +170,13 @@ void PacketQueue::clearPackets(ZMPacket *add_packet) {
         and
         add_packet->keyframe
         and
-        (packet_counts[video_stream_id] > max_video_packet_count)
+        (packet_counts[video_stream_id] > pre_event_video_packet_count)
         and 
         *(pktQueue.begin()) != add_packet
         )
      ) {
-    Debug(3, "stream index %d ?= video_stream_id %d, keyframe %d, keep_keyframes %d,  counts %d > max %d at begin %d",
+    Debug(3, "stream index %d ?= video_stream_id %d, keyframe %d, keep_keyframes %d,  counts %d > pre_event_count %d at begin %d",
-        add_packet->packet.stream_index, video_stream_id, add_packet->keyframe, keep_keyframes, packet_counts[video_stream_id], max_video_packet_count, 
+        add_packet->packet.stream_index, video_stream_id, add_packet->keyframe, keep_keyframes, packet_counts[video_stream_id], pre_event_video_packet_count, 
         ( *(pktQueue.begin()) != add_packet )
         );
     return;
@@ -155,7 +199,7 @@ void PacketQueue::clearPackets(ZMPacket *add_packet) {
 
   if (!keep_keyframes) {
     // If not doing passthrough, we don't care about starting with a keyframe so logic is simpler
-    while ((*pktQueue.begin() != add_packet) and (packet_counts[video_stream_id] > max_video_packet_count + tail_count)) {
+    while ((*pktQueue.begin() != add_packet) and (packet_counts[video_stream_id] > pre_event_video_packet_count + tail_count)) {
       ZMPacket *zm_packet = *pktQueue.begin();
       ZMLockedPacket *lp = new ZMLockedPacket(zm_packet);
       if (!lp->trylock()) break;
@@ -164,7 +208,7 @@ void PacketQueue::clearPackets(ZMPacket *add_packet) {
       pktQueue.pop_front();
       packet_counts[zm_packet->packet.stream_index] -= 1;
       Debug(1, "Deleting a packet with stream index:%d image_index:%d with keyframe:%d, video frames in queue:%d max: %d, queuesize:%d",
-          zm_packet->packet.stream_index, zm_packet->image_index, zm_packet->keyframe, packet_counts[video_stream_id], max_video_packet_count, pktQueue.size());
+          zm_packet->packet.stream_index, zm_packet->image_index, zm_packet->keyframe, packet_counts[video_stream_id], pre_event_video_packet_count, pktQueue.size());
       delete zm_packet;
     } // end while
     return;
@@ -201,7 +245,7 @@ void PacketQueue::clearPackets(ZMPacket *add_packet) {
         ++video_packets_to_delete;
           Debug(4, "Counted %d video packets. Which would leave %d in packetqueue tail count is %d",
               video_packets_to_delete, packet_counts[video_stream_id]-video_packets_to_delete, tail_count);
-        if (packet_counts[video_stream_id] - video_packets_to_delete <= max_video_packet_count + tail_count) {
+        if (packet_counts[video_stream_id] - video_packets_to_delete <= pre_event_video_packet_count + tail_count) {
           break;
         }
       }
@@ -221,7 +265,7 @@ void PacketQueue::clearPackets(ZMPacket *add_packet) {
       }
 
       Debug(1, "Deleting a packet with stream index:%d image_index:%d with keyframe:%d, video frames in queue:%d max: %d, queuesize:%d",
-          zm_packet->packet.stream_index, zm_packet->image_index, zm_packet->keyframe, packet_counts[video_stream_id], max_video_packet_count, pktQueue.size());
+          zm_packet->packet.stream_index, zm_packet->image_index, zm_packet->keyframe, packet_counts[video_stream_id], pre_event_video_packet_count, pktQueue.size());
       pktQueue.pop_front();
       packet_counts[zm_packet->packet.stream_index] -= 1;
       delete zm_packet;
@@ -238,7 +282,7 @@ ZMLockedPacket* PacketQueue::popPacket( ) {
 		return nullptr;
 	}
   Debug(4, "poPacket Mutex locking");
-  mutex.lock();
+  std::unique_lock<std::mutex> lck(mutex);
 
 	ZMPacket *zm_packet = pktQueue.front();
   for (
@@ -260,8 +304,6 @@ ZMLockedPacket* PacketQueue::popPacket( ) {
 	pktQueue.pop_front();
   packet_counts[zm_packet->packet.stream_index] -= 1;
 
-  mutex.unlock();
-
 	return lp;
 }  // popPacket
 
@@ -285,7 +327,7 @@ unsigned int PacketQueue::clear(unsigned int frames_to_keep, int stream_id) {
     return 0;
   }
   Debug(5, "Locking in clear");
-  mutex.lock();
+  std::unique_lock<std::mutex> lck(mutex);
 
   packetqueue_iterator it = pktQueue.end()--;  // point to last element instead of end
   ZMPacket *zm_packet = nullptr;
@@ -340,13 +382,7 @@ unsigned int PacketQueue::clear(unsigned int frames_to_keep, int stream_id) {
 
     delete_count += 1;
   } // while our iterator is not the first packet
-  zm_packet = nullptr; // tidy up for valgrind
   Debug(3, "Deleted %d packets, %d remaining", delete_count, pktQueue.size());
-  mutex.unlock();
-  return delete_count; 
-
-  Debug(3, "Deleted packets, resulting size is %d", pktQueue.size());
-  mutex.unlock();
   return delete_count; 
 } // end unsigned int PacketQueue::clear( unsigned int frames_to_keep, int stream_id )
 
@@ -389,7 +425,7 @@ unsigned int PacketQueue::clear(struct timeval *duration, int streamId) {
     return 0;
   }
   Debug(4, "Locking in clear");
-  mutex.lock();
+  std::unique_lock<std::mutex> lck(mutex);
 
   struct timeval keep_from;
   std::list<ZMPacket *>::reverse_iterator it = pktQueue.rbegin();
@@ -440,7 +476,6 @@ unsigned int PacketQueue::clear(struct timeval *duration, int streamId) {
   }
   if ( it == pktQueue.rend() ) {
     Debug(1, "Didn't find a keyframe before event starttime. keeping all" );
-    mutex.unlock();
     return 0;
   }
 
@@ -462,14 +497,10 @@ unsigned int PacketQueue::clear(struct timeval *duration, int streamId) {
     }  // end foreach iterator
     pktQueue.pop_front();
     packet_counts[zm_packet->packet.stream_index] -= 1;
-    //if ( zm_packet->image_index == -1 )
+    delete zm_packet;
-      delete zm_packet;
     deleted_frames += 1;
   }
-  zm_packet = nullptr;
   Debug(3, "Deleted %d frames", deleted_frames);
-  mutex.unlock();
-
   return deleted_frames;
 }
 
@@ -706,7 +737,13 @@ bool PacketQueue::is_there_an_iterator_pointing_to_packet(ZMPacket *zm_packet) {
 void PacketQueue::setMaxVideoPackets(int p) {
   max_video_packet_count = p;
   Debug(1, "Setting max_video_packet_count to %d", p);
-  if ( max_video_packet_count < 1 )
+  if ( max_video_packet_count < 0 )
-    max_video_packet_count = 1 ;
+    max_video_packet_count = 0 ;
+}
+void PacketQueue::setPreEventVideoPackets(int p) {
+  pre_event_video_packet_count = p;
+  Debug(1, "Setting pre_event_video_packet_count to %d", p);
+  if ( pre_event_video_packet_count < 1 )
+    pre_event_video_packet_count = 1;
   // We can simplify a lot of logic in queuePacket if we can assume at least 1 packet in queue
 }

src/zm_packetqueue.h

@@ -35,6 +35,8 @@ class PacketQueue {
 
     int video_stream_id;
     int max_video_packet_count; // allow a negative value to someday mean unlimited
+                                // This is now a hard limit on the # of video packets to keep in the queue so that we can limit ram
+    int pre_event_video_packet_count; // Was max_video_packet_count
     int max_stream_id;
     int *packet_counts;     /* packet count for each stream_id, to keep track of how many video vs audio packets are in the queue */
     bool deleting;
@@ -52,6 +54,7 @@ class PacketQueue {
 
     int addStream();
     void setMaxVideoPackets(int p);
+    void setPreEventVideoPackets(int p);
     void setKeepKeyframes(bool k) { keep_keyframes = k; };
 
     bool queuePacket(ZMPacket* packet);

version

@@ -1 +1 @@
-1.35.21
+1.35.22

web/includes/Monitor.php

@@ -84,6 +84,7 @@ class Monitor extends ZM_Object {
     'LabelY'      =>  0,
     'LabelSize'   =>  1,
     'ImageBufferCount'  =>  3,
+    'MaxImageBufferCount'  =>  0,
     'WarmupCount' =>  0,
     'PreEventCount' =>  5,
     'PostEventCount'  =>  5,

web/lang/en_gb.php

@@ -441,6 +441,7 @@ $SLANG = array(
     'Idle'                  => 'Idle',
     'Ignore'                => 'Ignore',
     'ImageBufferSize'       => 'Image Buffer Size (frames)',
+    'MaxImageBufferCount'   => 'Maximum Image Buffer Size (frames)',
     'Image'                 => 'Image',
     'Images'                => 'Images',
     'Include'               => 'Include',
@@ -1137,6 +1138,19 @@ $OLANG = array(
       optionally choose to not decode the H264/H265 packets.  This will drastically reduce cpu use
       but will make live view unavailable for this monitor.'
   ),
+  'ImageBufferCount' => array(
+    'Help' => '
+    Number of raw images available in /dev/shm. Currently should be set in the 3-5 range.  Used for live viewing.'
+  ),
+  'MaxImageBufferCount' => array(
+    'Help' => '
+    Maximum number of video packets that will be held in the packet queue.
+    The packetqueue will normally manage itself, keeping Pre Event Count frames or all since last keyframe if using 
+    passthrough mode. You can set a maximum to prevent the monitor from consuming too much ram, but your events might
+    not have all the frames they should if your keyframe interval is larger than this value.
+    You will get errors in your logs about this. So make sure your keyframe interval is low or you have enough ram.
+  '
+  ),
 
 //    'LANG_DEFAULT' => array(
 //        'Prompt' => "This is a new prompt for this option",

web/skins/classic/css/base/views/monitor.css

@@ -29,6 +29,7 @@ input[name="newMonitor[Refresh]"],
 input[name="newMonitor[LabelX]"],
 input[name="newMonitor[LabelY]"],
 input[name="newMonitor[ImageBufferCount]"],
+input[name="newMonitor[MaxImageBufferCount]"],
 input[name="newMonitor[WarmupCount]"],
 input[name="newMonitor[PreEventCount]"],
 input[name="newMonitor[PostEventCount]"],

web/skins/classic/views/js/monitor.js

@@ -48,7 +48,6 @@ function updateMonitorDimensions(element) {
       form.elements['newMonitor[Height]'].value = dimensions[1];
     }
   }
-  update_estimated_ram_use();
   return false;
 }
 
@@ -140,9 +139,6 @@ function initPage() {
       form.submit();
     };
   });
-  document.querySelectorAll('input[name="newMonitor[ImageBufferCount]"],input[name="newMonitor[Width]"],input[name="newMonitor[Height]"]').forEach(function(el) {
-    el.oninput = window['update_estimated_ram_use'].bind(el);
-  });
 
   document.querySelectorAll('select[name="newMonitor[Function]"]').forEach(function(el) {
     el.onchange = function() {
@@ -269,15 +265,6 @@ function random_WebColour() {
   );
 }
 
-function update_estimated_ram_use() {
-  var buffer_count = document.querySelectorAll('input[name="newMonitor[ImageBufferCount]"]')[0].value;
-  var width = document.querySelectorAll('input[name="newMonitor[Width]"]')[0].value;
-  var height = document.querySelectorAll('input[name="newMonitor[Height]"]')[0].value;
-  var colours = document.querySelectorAll('select[name="newMonitor[Colours]"]')[0].value;
-
-  document.getElementById('estimated_ram_use').innerHTML = human_filesize(buffer_count * width * height * colours, 0);
-}
-
 function updateLatitudeAndLongitude(latitude, longitude) {
   var form = document.getElementById('contentForm');
   form.elements['newMonitor[Latitude]'].value = latitude;

web/skins/classic/views/monitor.php

@@ -1059,9 +1059,13 @@ echo htmlSelect('newMonitor[OutputContainer]', $videowriter_containers, $monitor
     {
 ?>
             <tr>
-              <td class="text-right pr-3"><?php echo translate('ImageBufferSize') ?></td>
+              <td class="text-right pr-3"><?php echo translate('ImageBufferSize'); echo makeHelpLink('ImageBufferCount'); ?></td>
               <td><input type="number" name="newMonitor[ImageBufferCount]" value="<?php echo validHtmlStr($monitor->ImageBufferCount()) ?>" min="1"/></td>
             </tr>
+            <tr>
+              <td class="text-right pr-3"><?php echo translate('MaxImageBufferCount'); echo makeHelpLink('MaxImageBufferCount'); ?></td>
+              <td><input type="number" name="newMonitor[MaxImageBufferCount]" value="<?php echo validHtmlStr($monitor->MaxImageBufferCount()) ?>" min="0"/></td>
+            </tr>
             <tr>
               <td class="text-right pr-3"><?php echo translate('WarmupFrames') ?></td>
               <td><input type="number" name="newMonitor[WarmupCount]" value="<?php echo validHtmlStr($monitor->WarmupCount()) ?>" min="0"/></td>
@@ -1082,10 +1086,6 @@ echo htmlSelect('newMonitor[OutputContainer]', $videowriter_containers, $monitor
               <td class="text-right pr-3"><?php echo translate('AlarmFrameCount') ?></td>
               <td><input type="number" name="newMonitor[AlarmFrameCount]" value="<?php echo validHtmlStr($monitor->AlarmFrameCount()) ?>" min="1"/></td>
             </tr>
-            <tr>
-              <td class="text-right pr-3"><?php echo translate('Estimated Ram Use') ?></td>
-              <td id="estimated_ram_use"><?php echo human_filesize($monitor->ImageBufferCount() * $monitor->Width() * $monitor->Height() * $monitor->Colours(), 0) ?></td>
-            </tr>
 <?php
       break;
     }