Improved buffer handling

HISTORY

@@ -2967,7 +2967,7 @@ Video Disk Recorder Revision History
 - The 'radio' channel icon is now only displayed in the ST:TNG skin if the channel
   actually has an APID.
 
-2004-08-08: Version 1.3.13
+2004-10-16: Version 1.3.13
 
 - Fixed checking for the presence of NPTL (thanks to Jouni Karvo).
 - Making sure section filters are only set if the device actually has a lock
@@ -2976,3 +2976,33 @@ Video Disk Recorder Revision History
   Marco Schl<68>ssler).
 - Fixed a crash in case the last line in channels.conf is a group separator and
   that group is selected in the channel display (thanks to Dick Streefland).
+- Added cRingBufferLinear::Read() to read directly from a file handle into the
+  ring buffer.
+- Using timeouts in ring buffers to avoid 'usleep()'.
+- Clearing the 'Transfer Mode' ring buffer after clearing the device to avoid
+  an "almost full" ring buffer.
+- Removed locking from cRingBufferLinear for better performance under high load.
+- Using a cRingBufferLinear in cRemux to avoid unnecessary copying of data.
+- Using a cRingBufferLinear in cTSBuffer and filling it in a separate thread
+  to avoid buffer overflows. Plugins using cTSBuffer will need to remove the
+  call to the now obsolete Read() function (see cDvbDevice::GetTSPacket() for
+  the new usage of cTSBuffer).
+- cRemux::Process() has been split into Put(), Get() and Del() to allow for a
+  better decoupling of the remuxing and disk writing process. Plugins using
+  cRemux will need to be modified accordingly.
+- The actual disk writing in recordings is now done in a separate thread to
+  improve the overall throughput.
+- Changed cRemux so that it returns the maximum available amount of data with
+  each call, not just 2048 byte.
+- Added a visual display of all cRingBufferLinear buffers for debugging. To
+  activate it, define DEBUGRINGBUFFERS in ringbuffer.h.
+- Instead of cCondVar now using the new cCondWait (which also avoids a possible
+  "near miss" condition; thanks to Sascha Volkenandt for pointing out this one).
+  cCondVar is still present for plugins that use it (and VDR itself also still
+  uses it in cRemote).
+- The cRingBuffer now does EnableGet()/EnablePut() only if the buffer is more than
+  one third full or empty, respectively. This dramatically improves recording
+  performance and reduces system load (thanks to Marco Schl<68><6C>ler for doing some
+  testing regarding buffer performance and giving me some hints that finally led
+  to finding out that this was the basic problem causing buffer overflows).
+- Improved Transfer Mode (thanks to Marco Schl<68><6C>ler for suggestions and testing).