Update the xineScope to remove global variables.

This patch updates xineScope.c to better align with Amarok's code. As a
result, the analyzer is more accurate.  For instance, when playing an
audio file and there is a silent spot, the blocks will correctly "drop"
to the bottom, leaving an empty analyzer.  The previous behaviour would
leave some blocks "stuck" in their position

See: TDE/codeine#23
Signed-off-by: mio <[email protected]>
(cherry picked from commit ff2a5768dd4d199cb8bbbe2af4ea3fbb68a489f3)

1 files changed, 56 insertions, 29 deletions

diff --git a/src/app/xineEngine.cpp b/src/app/xineEngine.cpp
index 2cb9cd3..7f73e0d 100644
--- a/src/app/xineEngine.cpp
+++ b/src/app/xineEngine.cpp
@@ -36,8 +36,9 @@ VideoWindow::VideoWindow( TQWidget *parent )
       , m_eventQueue( nullptr )
       , m_videoPort( nullptr )
       , m_audioPort( nullptr )
-      , m_scope( nullptr )
+      , m_post( nullptr )
       , m_xine( nullptr )
+      , m_scope( Analyzer::SCOPE_SIZE * 2 ) // Multiply by two to account for interleaved PCM.
       , m_current_vpts( 0 )
 {
    DEBUG_BLOCK
@@ -51,10 +52,6 @@ VideoWindow::VideoWindow( TQWidget *parent )
    setPaletteBackgroundColor( TQt::black );
    setFocusPolicy( ClickFocus );
 
-   //TODO sucks
-   //TODO namespace this?
-   myList->next = myList; //init the buffer list
-
    // Detect xine version, this is used for volume adjustment.
    // Xine versions prior to 1.2.13 use linear volume, so the engine uses logarithmic volume.
    // Xine versions starting from 1.2.13 use logarithmic volume, so the engine uses linear volume.
@@ -101,7 +98,7 @@ VideoWindow::~VideoWindow()
    if( m_stream )     xine_dispose( m_stream );
    if( m_audioPort )  xine_close_audio_driver( m_xine, m_audioPort );
    if( m_videoPort )  xine_close_video_driver( m_xine, m_videoPort );
-   if( m_scope )      xine_post_dispose( m_xine, m_scope );
+   if( m_post )       xine_post_dispose( m_xine, m_post );
    if( m_xine )       xine_exit( m_xine );
 
    cleanUpVideo();
@@ -119,7 +116,7 @@ VideoWindow::init()
    if( !m_xine )
       return false;
 
-   xine_engine_set_param( m_xine, XINE_ENGINE_PARAM_VERBOSITY, 99 );
+   xine_engine_set_param(m_xine, XINE_ENGINE_PARAM_VERBOSITY, XINE_VERBOSITY_DEBUG);
 
    debug() << "xine_config_load()\n";
    xine_config_load( m_xine, TQFile::encodeName( TQDir::homeDirPath() + "/.xine/config" ) );
@@ -161,9 +158,9 @@ VideoWindow::init()
    debug() << "scope_plugin_new()\n";
 #if XINE_MAJOR_VERSION > 1 || (XINE_MAJOR_VERSION == 1 && XINE_MINOR_VERSION > 2) || \
    (XINE_MAJOR_VERSION == 1 && XINE_MINOR_VERSION == 2 && XINE_SUB_VERSION >= 10)
-   m_scope = xine_post_init( m_xine, "codeine-scope", 1, &m_audioPort, nullptr );
+   m_post = xine_post_init( m_xine, "codeine-scope", 1, &m_audioPort, nullptr );
 #else
-   m_scope = scope_plugin_new( m_xine, m_audioPort );
+   m_post = scope_plugin_new( m_xine, m_audioPort );
 
    //FIXME this one seems to make seeking unstable for Codeine, perhaps
    xine_set_param( m_stream, XINE_PARAM_METRONOM_PREBUFFER, 6000 ); //less buffering, faster seeking..
@@ -281,9 +278,9 @@ VideoWindow::load( const KURL &url )
       // FIXME leaves one erroneous buffer
       timerEvent( nullptr );
 
-      if( m_scope ) {
+      if( m_post ) {
          xine_post_out_t *source = xine_get_audio_source( m_stream );
-         xine_post_in_t  *target = (xine_post_in_t*)xine_post_input( m_scope, const_cast<char*>("audio in") );
+         xine_post_in_t  *target = (xine_post_in_t*)xine_post_input( m_post, const_cast<char*>("audio in") );
          xine_post_wire( source, target );
       }
 
@@ -373,6 +370,8 @@ VideoWindow::stop()
 {
    xine_stop( m_stream );
 
+   std::fill(m_scope.begin(), m_scope.end(), 0);
+
    announceStateChange();
 }
 
@@ -590,7 +589,7 @@ VideoWindow::setStreamParameter( int value )
    else if( sender == "volume" )
    {
       parameter = XINE_PARAM_AUDIO_AMP_LEVEL;
-      value = 100 - value; // TQt sliders are wrong way round when vertical
+      value = 100 - value; // TQt sliders are the wrong way round when vertical
       if (s_logarithmicVolume)
       {
         value = makeVolumeLogarithmic(value);
@@ -607,16 +606,25 @@ VideoWindow::scope()
 {
    using Analyzer::SCOPE_SIZE;
 
-   static Engine::Scope scope( SCOPE_SIZE );
+   if (!m_post || !m_stream || xine_get_status(m_stream) != XINE_STATUS_PLAY)
+   {
+      return m_scope;
+   }
 
-   if( xine_get_status( m_stream ) != XINE_STATUS_PLAY )
-      return scope;
+   MyNode *const myList        = scope_plugin_list(m_post);
+   const int64_t pts_per_smpls = scope_plugin_pts_per_smpls(m_post);
+   const int channels          = scope_plugin_channels(m_post);
+   int scopeIdx = 0;
+
+   if (channels > 2)
+   {
+      return m_scope;
+   }
 
    //prune the buffer list and update the m_current_vpts timestamp
    timerEvent( nullptr );
 
-   const int64_t pts_per_smpls = scope_plugin_pts_per_smpls(m_scope);
-   for( int channels = xine_get_stream_info( m_stream, XINE_STREAM_INFO_AUDIO_CHANNELS ), frame = 0; frame < SCOPE_SIZE; )
+   for (int n, frame = 0; frame < SCOPE_SIZE; /* no-op */)
    {
       MyNode *best_node = nullptr;
 
@@ -637,10 +645,10 @@ VideoWindow::scope()
       data16  = best_node->mem;
       data16 += diff;
 
-      diff += diff % channels; //important correction to ensure we don't overflow the buffer
-      diff /= channels;
+      diff += diff % channels; // important correction to ensure we don't overflow the buffer.
+      diff /= channels;        // use units of frames, not samples.
 
-      int
+      // calculate the number of available samples in this buffer.
       n  = best_node->num_frames;
       n -= diff;
       n += frame; //clipping for # of frames we need
@@ -650,33 +658,52 @@ VideoWindow::scope()
 
       for( int a, c; frame < n; ++frame, data16 += channels ) {
          for( a = c = 0; c < channels; ++c )
-            a += data16[c];
-
-         a /= channels;
-         scope[frame] = a;
+         {
+            // now we give interleaved PCM to the scope.
+            m_scope[scopeIdx++] = data16[c];
+            if (channels == 1)
+            {
+               // Duplicate mono samples.
+               m_scope[scopeIdx++] = data16[c];
+            }
+         }
       }
 
       m_current_vpts = best_node->vpts_end;
       m_current_vpts++; //FIXME needs to be done for some reason, or you get situations where it uses same buffer again and again
    }
 
-   return scope;
+   return m_scope;
 }
 
 void
 VideoWindow::timerEvent( TQTimerEvent* )
 {
+   if (!m_stream)
+   {
+      return;
+   }
+
    /// here we prune the buffer list regularly
-   MyNode * const first_node = myList->next;
-   MyNode const * const list_end = myList;
+   MyNode *myList = scope_plugin_list(m_post);
+
+   if (!myList)
+   {
+      return;
+   }
+
+   // We operate on a subset of the list for thread-safety.
+   MyNode *const firstNode = myList->next;
+   const MyNode *const listEnd = myList;
 
+   // If we're not playing or paused, empty the list.
    m_current_vpts = (xine_get_status( m_stream ) == XINE_STATUS_PLAY)
          ? xine_get_current_vpts( m_stream )
          : std::numeric_limits<int64_t>::max();
 
-   for( MyNode *prev = first_node, *node = first_node->next; node != list_end; node = node->next )
+   for( MyNode *prev = firstNode, *node = firstNode->next; node != listEnd; node = node->next )
    {
-      // we never delete first_node
+      // we never delete firstNode
       // this maintains thread-safety
       if( node->vpts_end < m_current_vpts ) {
          prev->next = node->next;