Scope support for the VLC engine

CMakeLists.txt

@@ -37,6 +37,7 @@ if(WIN32)
 else(WIN32)
   pkg_check_modules(TAGLIB taglib)
   pkg_check_modules(LIBVLC libvlc)
+  pkg_check_modules(VLC_PLUGIN vlc-plugin)
 
   if (TAGLIB_VERSION VERSION_LESS 1.6)
     message(FATAL_ERROR "Taglib version 1.6 or greater is required")
@@ -69,6 +70,7 @@ include(${QT_USE_FILE})
 include_directories(${Boost_INCLUDE_DIRS})
 include_directories(${TAGLIB_INCLUDE_DIRS})
 include_directories(${LIBVLC_INCLUDE_DIRS})
+include_directories(${VLC_PLUGIN_INCLUDE_DIRS})
 include_directories(${LASTFM_INCLUDE_DIRS})
 include_directories("3rdparty/qsqlite")
 
@@ -88,6 +90,7 @@ add_definitions(-DQXT_STATIC -DBUILD_QXT_GUI -DBUILD_QXT_CORE)
 # Subdirectories
 add_subdirectory(3rdparty/qtsingleapplication)
 add_subdirectory(3rdparty/qxt)
+add_subdirectory(vlcplugins)
 add_subdirectory(src)
 
 add_subdirectory(tests)
@@ -97,6 +100,14 @@ if (WIN32)
   add_subdirectory(3rdparty/qsqlite)
 endif(WIN32)
 
+# Install libraries to the right place
+set (LIBRARY_INSTALL_DIR lib)
+if (EXISTS "${CMAKE_INSTALL_PREFIX}/lib32/" AND CMAKE_SIZEOF_VOID_P EQUAL 4)
+  set (LIBRARY_INSTALL_DIR lib32)
+elif (EXISTS "${CMAKE_INSTALL_PREFIX}/lib64/" AND CMAKE_SIZEOF_VOID_P EQUAL 8)
+  set (LIBRARY_INSTALL_DIR lib64)
+endif ()
+
 # Uninstall support
 configure_file(
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake_uninstall.cmake.in"

src/engines/vlcengine.cpp

@@ -19,12 +19,17 @@
 
 #include <QTimer>
 #include <QtDebug>
+#include <QMutexLocker>
+#include <QTime>
 
 #include <boost/bind.hpp>
 
+VlcEngine* VlcEngine::sInstance = NULL;
+
 VlcEngine::VlcEngine()
   : instance_(NULL),
     player_(NULL),
+    scope_data_(4096),
     state_(Engine::Empty)
 {
   static const char * const args[] = {
@@ -32,7 +37,10 @@ VlcEngine::VlcEngine()
     "--ignore-config",    // Don't use VLC's config
     "--extraintf=logger", // log anything
     "--verbose=2",        // be much more verbose then normal for debugging purpose
-    //"--plugin-path=C:\\vlc-0.9.9-win32\\plugins\\"
+
+    // Our scope plugin
+    "--audio-filter=clementine_scope",
+    "--no-plugins-cache",
 
 #if defined(Q_OS_UNIX) && !defined(Q_OS_MAC)
     "--aout=alsa",        // The default, pulseaudio, is buggy
@@ -62,6 +70,8 @@ VlcEngine::VlcEngine()
   AttachCallback(player_em, libvlc_MediaPlayerStopped, StateChangedCallback);
   AttachCallback(player_em, libvlc_MediaPlayerEndReached, StateChangedCallback);
   HandleErrors();
+
+  sInstance = this;
 }
 
 VlcEngine::~VlcEngine() {
@@ -204,3 +214,33 @@ void VlcEngine::HandleErrors() const {
     qFatal("libvlc error: %s", libvlc_exception_get_message(&exception_));
   }
 }
+
+void VlcEngine::SetScopeData(float* data, int size) {
+  if (!sInstance)
+    return;
+
+  QMutexLocker l(&sInstance->scope_mutex_);
+
+  // This gets called by our VLC plugin.  Just push the data on to the end of
+  // the circular buffer and let it get consumed by scope()
+  for (int i=0 ; i<size ; ++i) {
+    sInstance->scope_data_.push_back(data[i]);
+  }
+}
+
+const Engine::Scope& VlcEngine::scope() {
+  QMutexLocker l(&scope_mutex_);
+
+  // Leave the scope unchanged if there's not enough data
+  if (scope_data_.size() < SCOPESIZE)
+    return m_scope;
+
+  // Take the samples off the front of the circular buffer
+  for (uint i=0 ; i<SCOPESIZE ; ++i)
+    m_scope[i] = scope_data_[i] * (1 << 15);
+
+  // Remove the samples from the buffer.  Unfortunately I think this is O(n) :(
+  scope_data_.rresize(qMax(0, int(scope_data_.size()) - SCOPESIZE*2));
+
+  return m_scope;
+}

src/engines/vlcengine.h

@@ -20,6 +20,9 @@
 #include "enginebase.h"
 
 #include <vlc/vlc.h>
+#include <boost/circular_buffer.hpp>
+
+#include <QMutex>
 
 class QTimer;
 
@@ -46,6 +49,9 @@ class VlcEngine : public Engine::Base {
 
   void seek( uint ms );
 
+  static void SetScopeData(float* data, int size);
+  const Engine::Scope& scope();
+
  protected:
   void setVolumeSW( uint percent );
 
@@ -56,10 +62,15 @@ class VlcEngine : public Engine::Base {
   static void StateChangedCallback(const libvlc_event_t* e, void* data);
 
  private:
+  static VlcEngine* sInstance;
+
   libvlc_exception_t exception_;
   libvlc_instance_t* instance_;
   libvlc_media_player_t* player_;
 
+  QMutex scope_mutex_;
+  boost::circular_buffer<float> scope_data_;
+
   Engine::State state_;
 };
 

vlcplugins/CMakeLists.txt

@@ -0,0 +1,24 @@
+cmake_minimum_required(VERSION 2.6)
+
+set(CMAKE_C_FLAGS "-Wall")
+set(CMAKE_CXX_FLAGS "-Wnon-virtual-dtor -Woverloaded-virtual -Wall")
+
+# Source files
+set(CLEMENTINE-SCOPE-SOURCES
+  clementinescope.cpp
+)
+
+include_directories(${CMAKE_CURRENT_BINARY_DIR} ${CMAKE_CURRENT_SOURCE_DIR})
+include_directories("${CMAKE_CURRENT_SOURCE_DIR}/../src")
+
+add_library(clementine_scope SHARED
+  ${CLEMENTINE-SCOPE-SOURCES}
+)
+target_link_libraries(clementine_scope
+  ${VLC_PLUGIN_LIBRARIES}
+  ${QT_LIBRARIES}
+)
+
+install(TARGETS clementine_scope
+  LIBRARY DESTINATION ${VLC_PLUGIN_LIBDIR}/vlc/clementine
+)

vlcplugins/clementinescope.cpp

@@ -0,0 +1,70 @@
+/* This file is part of Clementine.
+
+   Clementine 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.
+
+   Clementine 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 Clementine.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#define __PLUGIN__
+#define MODULE_STRING "clementine_scope"
+#define MODULE_NAME clementine_scope
+
+#include "engines/vlcengine.h"
+
+#include <vlc/vlc.h>
+#include <vlc/plugins/vlc_common.h>
+#include <vlc/plugins/vlc_plugin.h>
+#include <vlc/plugins/vlc_aout.h>
+
+#include <QtGlobal>
+
+// Forward declarations
+static int  Open         ( vlc_object_t * );
+static void DoWork( aout_instance_t *p_aout, aout_filter_t *p_filter,
+                    aout_buffer_t *p_in_buf, aout_buffer_t *p_out_buf );
+
+// Module definition
+vlc_module_begin ()
+  set_description("Internal plugin for Clementine's analyzer")
+  set_shortname("clementine_scope")
+  set_category( CAT_AUDIO )
+  set_subcategory( SUBCAT_AUDIO_VISUAL )
+  set_capability( "audio filter", 0 )
+  set_callbacks( Open, 0 )
+  add_shortcut( "clementine_scope")
+vlc_module_end ()
+
+
+// Called once for every track
+static int Open( vlc_object_t *p_this ) {
+  aout_filter_t     *p_filter = (aout_filter_t *)p_this;
+
+  if( ( p_filter->input.i_format != VLC_FOURCC('f','l','3','2') &&
+        p_filter->input.i_format != VLC_FOURCC('f','i','3','2') ) ) {
+    return VLC_EGENERIC;
+  }
+
+  p_filter->pf_do_work = DoWork;
+  p_filter->b_in_place= 1;
+
+  return VLC_SUCCESS;
+}
+
+// Called continuously while a track is playing
+static void DoWork( aout_instance_t *p_aout, aout_filter_t *p_filter,
+                    aout_buffer_t *p_in_buf, aout_buffer_t *p_out_buf ) {
+  Q_UNUSED(p_aout);
+  Q_UNUSED(p_out_buf);
+  VlcEngine::SetScopeData(
+      reinterpret_cast<float*>(p_in_buf->p_buffer),
+      p_in_buf->i_nb_samples * aout_FormatNbChannels(&p_filter->input));
+}