First attempt to add DSP support

src/libtomahawk/CMakeLists.txt

@@ -215,6 +215,7 @@ list(APPEND libSources
 
     audio/AudioEngine.cpp
     audio/AudioOutput.cpp
+    audio/VlcDspHack.cpp
 
     collection/Collection.cpp
     collection/ArtistsRequest.cpp
@@ -506,6 +507,7 @@ TARGET_LINK_LIBRARIES( tomahawklib
     LINK_PRIVATE
     ${PHONON_LIBRARY}
     ${LIBVLC_LIBRARY}
+    ${LIBVLCCORE_LIBRARY}
 
     # Thirdparty shipped with tomahawk
     ${LIBPORTFWD_LIBRARIES}

src/libtomahawk/audio/AudioEngine.cpp

@@ -1341,7 +1341,7 @@ AudioEngine::setCurrentTrackPlaylist( const playlistinterface_ptr& playlist )
 
 
 void
-AudioEngine::setDspCallback( void ( *cb ) ( signed short*, int, int ) )
+AudioEngine::setDspCallback( void ( *cb ) ( float*, int, int ) )
 {
     Q_D( AudioEngine );
 

src/libtomahawk/audio/AudioEngine.h

@@ -109,7 +109,7 @@ public:
      */
     qint64 currentTrackTotalTime() const;
 
-    void setDspCallback( void ( *cb ) ( signed short* samples, int nb_channels, int nb_samples ) );
+    void setDspCallback( void ( *cb ) ( float* samples, int nb_channels, int nb_samples ) );
 
 public slots:
     void playPause();

src/libtomahawk/audio/AudioOutput.cpp

@@ -20,6 +20,7 @@
 
 #include "AudioEngine.h"
 #include "AudioOutput.h"
+#include "VlcDspHack.h"
 
 #include "utils/Logger.h"
 
@@ -85,10 +86,11 @@ AudioOutput::AudioOutput( QObject* parent )
     args << "--no-snapshot-preview";
     args << "--no-xlib";
     args << "--services-discovery=''";
-//    args << "--no-one-instance";
     args << "--no-video";
-//    args << "--audio-filter=dsp";
-//    args << QString("--dsp-callback=%1").arg((quint64)&AudioOutput::s_dspCallback, 0, 16).toAscii();
+#ifdef VLC_DSP_PLUGIN_ENABLED
+    args << "--audio-filter=dsp";
+    args << QString("--dsp-callback=%1").arg((quint64)&AudioOutput::s_dspCallback, 0, 16).toAscii();
+#endif
 
     QVarLengthArray< const char * , 64 > vlcArgs( args.size() );
     for ( int i = 0 ; i < args.size() ; ++i ) {
@@ -138,6 +140,8 @@ AudioOutput::AudioOutput( QObject* parent )
 AudioOutput::~AudioOutput()
 {
     tDebug() << Q_FUNC_INFO;
+
+    // TODO
 }
 
 
@@ -218,6 +222,10 @@ AudioOutput::setCurrentSource(MediaStream* stream)
 
     libvlc_media_player_set_media( vlcPlayer, vlcMedia );
 
+#ifdef VLC_DSP_PLUGIN_ENABLED
+    // This is very, very tricky
+    VlcDspHackInstall( vlcPlayer );
+#endif
 
     if ( stream->type() == MediaStream::Url ) {
         m_totalTime = libvlc_media_get_duration( vlcMedia );
@@ -479,9 +487,9 @@ AudioOutput::vlcEventCallback( const libvlc_event_t* event, void* opaque )
 
 
 void
-AudioOutput::s_dspCallback( signed short* samples, int nb_channels, int nb_samples )
+AudioOutput::s_dspCallback( float* samples, int nb_channels, int nb_samples )
 {
-    tDebug() << Q_FUNC_INFO;
+//    tDebug() << Q_FUNC_INFO;
 
     if ( AudioOutput::instance()->dspPluginCallback ) {
         AudioOutput::instance()->dspPluginCallback( samples, nb_channels, nb_samples );
@@ -490,7 +498,7 @@ AudioOutput::s_dspCallback( signed short* samples, int nb_channels, int nb_sampl
 
 
 void
-AudioOutput::setDspCallback( void ( *cb ) ( signed short*, int, int ) )
+AudioOutput::setDspCallback( void ( *cb ) ( float*, int, int ) )
 {
     dspPluginCallback = cb;
 }

src/libtomahawk/audio/AudioOutput.h

@@ -61,7 +61,7 @@ public:
     qint64 totalTime();
     void setAutoDelete ( bool ad );
 
-    void setDspCallback( void ( *cb ) ( signed short*, int, int ) );
+    void setDspCallback( void ( *cb ) ( float*, int, int ) );
 
     static AudioOutput* instance();
 
@@ -78,7 +78,7 @@ private:
     void setTotalTime( qint64 time );
 
     static void vlcEventCallback( const libvlc_event_t *event, void *opaque );
-    static void s_dspCallback( signed short* samples, int nb_channels, int nb_samples );
+    static void s_dspCallback( float* samples, int nb_channels, int nb_samples );
 
     static AudioOutput* s_instance;
     AudioState currentState;
@@ -91,7 +91,7 @@ private:
     qint64 m_totalTime;
     bool m_aboutToFinish;
 
-    void ( *dspPluginCallback ) ( signed short* samples, int nb_channels, int nb_samples );
+    void ( *dspPluginCallback ) ( float* samples, int nb_channels, int nb_samples );
 
     libvlc_instance_t* vlcInstance;
     libvlc_media_player_t* vlcPlayer;

src/libtomahawk/audio/VlcDspHack.cpp

@@ -0,0 +1,24 @@
+#include "VlcDspHack_p.h"
+
+#ifdef VLC_DSP_PLUGIN_ENABLED
+
+void
+VlcDspHackInstall( libvlc_media_player_t* vlcPlayer )
+{
+    if ( vlcPlayer->input.p_resource != 0 ) {
+        audio_output_t *aout = input_resource_GetAout( vlcPlayer->input.p_resource );
+        if ( aout != 0 ) {
+            var_Create( (vlc_object_t*)aout, "audio-filter", 0x0040 /*VLC_VAR_STRING*/ );
+
+            vlc_value_t val;
+            val.psz_string = (char*)"dsp";
+            var_SetChecked( (vlc_object_t*)aout, "audio-filter", 0x0040 /*VLC_VAR_STRING*/, val );
+
+            aout->event.restart_request( aout, 1 /*AOUT_RESTART_FILTERS*/ );
+
+            input_resource_PutAout( vlcPlayer->input.p_resource, aout );
+        }
+    }
+}
+
+#endif // VLC_DSP_PLUGIN_ENABLED

src/libtomahawk/audio/VlcDspHack.h

@@ -0,0 +1,28 @@
+#ifndef VLCDSPHACK_H
+#define VLCDSPHACK_H
+
+/*
+ * Very tricky technique to enable DSP plugin support
+ * There is no other way to do this with libvlc for the moment
+ * 
+ * A VLC audio filter plugin specificaly made for Tomahawk
+ * is necessary to get it functionning
+ * 
+ * TODO : Check thoroughly if both libvlc_media_player_t and audio_output
+ * structures are identical to those in the running libvlccore.so
+ * (checking if libVLC version is >= than the one used to compile Tomahawk
+ *  and verifying pointers integrity should be enough.
+ *  + check if audio filter "dsp" is present in libVLC plugins list)
+*/
+
+//#define VLC_DSP_PLUGIN_ENABLED
+
+#ifdef VLC_DSP_PLUGIN_ENABLED
+
+struct libvlc_media_player_t;
+
+void VlcDspHackInstall( libvlc_media_player_t* vlcPlayer );
+
+#endif // VLC_DSP_PLUGIN_ENABLED
+
+#endif // VLCDSPHACK_H

src/libtomahawk/audio/VlcDspHack_p.h

@@ -0,0 +1,107 @@
+#ifndef VLCDSPHACK_P_H
+#define VLCDSPHACK_P_H
+
+#include "VlcDspHack.h"
+
+#ifdef VLC_DSP_PLUGIN_ENABLED
+
+#include <pthread.h>
+
+#include <vlc/libvlc.h>
+#include <vlc/libvlc_media.h>
+#include <vlc/libvlc_media_player.h>
+#include <vlc/libvlc_events.h>
+#include <vlc/libvlc_version.h>
+
+// TODO : Replace all these copy-pasted strutures by vlc/plugins/?.h includes
+
+typedef struct audio_output audio_output_t;
+typedef struct input_resource_t input_resource_t;
+typedef struct vlc_object_t vlc_object_t;
+typedef struct vlc_list_t vlc_list_t;
+typedef int64_t mtime_t;
+typedef pthread_mutex_t vlc_mutex_t;
+
+typedef union
+{
+    int64_t         i_int;
+    bool            b_bool;
+    float           f_float;
+    char *          psz_string;
+    void *          p_address;
+    vlc_object_t *  p_object;
+    vlc_list_t *    p_list;
+    mtime_t         i_time;
+    struct { int32_t x; int32_t y; } coords;
+
+} vlc_value_t;
+
+struct audio_output
+{
+    const char *psz_object_type;
+    char *psz_header;
+    int  i_flags;
+    bool b_force;
+    void *p_libvlc;
+    void *  p_parent;
+
+   void *sys;
+    int (*start)(audio_output_t *, void *fmt);
+    void (*stop)(audio_output_t *);
+    int (*time_get)(audio_output_t *, void *delay);
+    void (*play)(audio_output_t *, void *);
+    void (*pause)( audio_output_t *, bool pause, mtime_t date);
+    void (*flush)( audio_output_t *, bool wait);
+    int (*volume_set)(audio_output_t *, float volume);
+    int (*mute_set)(audio_output_t *, bool mute);
+    int (*device_select)(audio_output_t *, const char *id);
+    struct {
+        void (*volume_report)(audio_output_t *, float);
+        void (*mute_report)(audio_output_t *, bool);
+        void (*policy_report)(audio_output_t *, bool);
+        void (*device_report)(audio_output_t *, const char *);
+        void (*hotplug_report)(audio_output_t *, const char *, const char *);
+        int (*gain_request)(audio_output_t *, float);
+        void (*restart_request)(audio_output_t *, unsigned);
+    } event;
+};
+
+
+struct libvlc_media_player_t
+{
+    const char *psz_object_type;
+    char *psz_header;
+    int  i_flags;
+    bool b_force;
+    void *p_libvlc;
+    void *p_parent;
+
+    int                i_refcount;
+    vlc_mutex_t        object_lock;
+
+    struct
+    {
+        void             *p_thread;
+        input_resource_t *p_resource;
+        vlc_mutex_t       lock;
+    } input;
+
+    void *p_libvlc_instance;
+    void *p_md;
+    void *p_event_manager;
+    int   state;
+};
+
+extern "C" {
+    audio_output_t* input_resource_GetAout(input_resource_t*);
+    void input_resource_PutAout(input_resource_t*, audio_output_t*);
+    int var_Create(vlc_object_t *, const char *, int );
+    int var_SetChecked( vlc_object_t *, const char *, int, vlc_value_t );
+    static inline void aout_RestartRequest(audio_output_t *aout, unsigned mode){
+        aout->event.restart_request(aout, mode);
+    }
+};
+
+#endif // VLC_DSP_PLUGIN_ENABLED
+
+#endif // VLCDSPHACK_P_H