Implement infrastructure for audio backends integration.

Main features of this infrastructure are: - backends compiled into the ui are selected at compile time via a HAVE_XXX_BACKEND macro / Makefile variable. This allow frontend maintainer to select which audio backend is adapted for their platform and avoid potential unwanted dependencies. - audio backend selection at runtime is done using the --audio parameter. This allow the user to choose which audio backend (among those available) to use. - it is possible to list available audio backends on the command line (--audio list).
mupen64plus · Mar 7, 2015 · b1e1fa8 · b1e1fa8
1 parent 398b96c
commit b1e1fa8
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diff --git a/projects/VisualStudio2013/mupen64plus-ui-console.vcxproj b/projects/VisualStudio2013/mupen64plus-ui-console.vcxproj
@@ -118,6 +118,9 @@ copy ..\..\..\mupen64plus-win32-deps\zlib-1.2.3\bin\*.dll "$(OutDir)"
     </PostBuildEvent>
   </ItemDefinitionGroup>
   <ItemGroup>
+    <ClCompile Include="..\..\src\backends\audio\dummy_audio_backend.c" />
+    <ClCompile Include="..\..\src\backends\audio\sdl_audio_backend.c" />
+    <ClCompile Include="..\..\src\backend_factory.c" />
     <ClCompile Include="..\..\src\cheat.c" />
     <ClCompile Include="..\..\src\compare_core.c" />
     <ClCompile Include="..\..\src\core_interface.c" />
@@ -127,6 +130,9 @@ copy ..\..\..\mupen64plus-win32-deps\zlib-1.2.3\bin\*.dll "$(OutDir)"
     <ClCompile Include="..\..\src\plugin.c" />
   </ItemGroup>
   <ItemGroup>
+    <ClInclude Include="..\..\src\backends\audio\dummy_audio_backend.h" />
+    <ClInclude Include="..\..\src\backends\audio\sdl_audio_backend.h" />
+    <ClInclude Include="..\..\src\backend_factory.h" />
     <ClInclude Include="..\..\src\cheat.h" />
     <ClInclude Include="..\..\src\compare_core.h" />
     <ClInclude Include="..\..\src\core_interface.h" />
@@ -140,4 +146,4 @@ copy ..\..\..\mupen64plus-win32-deps\zlib-1.2.3\bin\*.dll "$(OutDir)"
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
+</Project>
diff --git a/projects/unix/Makefile b/projects/unix/Makefile
@@ -225,11 +225,19 @@ endif
 
 # list of source files to compile
 SOURCE = \
+	$(SRCDIR)/backend_factory.c \
 	$(SRCDIR)/cheat.c \
 	$(SRCDIR)/compare_core.c \
 	$(SRCDIR)/core_interface.c \
 	$(SRCDIR)/main.c \
-	$(SRCDIR)/plugin.c
+	$(SRCDIR)/plugin.c \
+	$(SRCDIR)/backends/audio/dummy_audio_backend.c
+
+# optional audio backends
+ifeq ($(HAVE_SDL_AUDIO_BACKEND),1)
+	CFLAGS += '-DHAVE_SDL_AUDIO_BACKEND'
+	SOURCE += $(SRCDIR)/backends/audio/sdl_audio_backend.c
+endif
 
 ifeq ($(OS), MINGW)
 SOURCE += \
@@ -265,7 +273,9 @@ targets:
 	@echo "    OPTFLAGS=flags == compiler optimization (default: -O3 -flto)"
 	@echo "    WARNFLAGS=flag == compiler warning levels (default: -Wall)"
 	@echo "    PIE=(1|0)      == Force enable/disable of position independent executables"
-	@echo "    POSTFIX=name  == String added to the name of the the build (default: '')"
+	@echo "    POSTFIX=name   == String added to the name of the the build (default: '')"
+	@echo "  Optional backends:"
+	@echo "	   HAVE_SDL_AUDIO_BACKEND=(1|0) == enable|disable SDL audio backend compilation (default:0)"
 	@echo "  Install Options:"
 	@echo "    PREFIX=path    == install/uninstall prefix (default: /usr/local/)"
 	@echo "    BINDIR=path    == path to install mupen64plus binary (default: PREFIX/bin/)"

diff --git a/src/backend_factory.c b/src/backend_factory.c
@@ -0,0 +1,59 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ *   Mupen64plus-ui-console - audio_backend_factory.c                      *
+ *   Mupen64Plus homepage: http://code.google.com/p/mupen64plus/           *
+ *   Copyright (C) 2015 Bobby Smiles                                       *
+ *                                                                         *
+ *   This program 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 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program 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 this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.          *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#include "backend_factory.h"
+
+#include "backends/audio/dummy_audio_backend.h"
+
+#ifdef HAVE_SDL_AUDIO_BACKEND
+#include "backends/audio/sdl_audio_backend.h"
+#endif
+
+#include <string.h>
+
+
+const struct backend_factory* const audio_backend_factories[] =
+{
+    &dummy_audio_backend_factory,
+#ifdef HAVE_SDL_AUDIO_BACKEND
+    &sdl_audio_backend_factory,
+#endif
+    NULL /* end of array sentinel */
+};
+
+const struct backend_factory* get_backend_factory(const struct backend_factory* const* factories, const char* name)
+{
+    if (factories != NULL && name != NULL)
+    {
+        while((*factories) != NULL)
+        {
+            if (strcmp(name, (*factories)->name) == 0)
+            {
+                return *factories;
+            }
+
+            ++factories;
+        }
+    }
+
+    return NULL;
+}
+
diff --git a/src/backend_factory.h b/src/backend_factory.h
@@ -0,0 +1,38 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ *   Mupen64plus-ui-console - backend_factory.h                            *
+ *   Mupen64Plus homepage: http://code.google.com/p/mupen64plus/           *
+ *   Copyright (C) 2015 Bobby Smiles                                       *
+ *                                                                         *
+ *   This program 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 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program 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 this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.          *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#ifndef M64P_BACKEND_FACTORY_H
+#define M64P_BACKEND_FACTORY_H
+
+#include "m64p_types.h"
+
+struct backend_factory
+{
+    const char* name;
+    m64p_error  (*init)(struct m64p_audio_backend* backend);
+    void        (*release)(struct m64p_audio_backend* backend);
+};
+
+const struct backend_factory*
+get_backend_factory(const struct backend_factory* const* factories, const char* name);
+
+extern const struct backend_factory* const audio_backend_factories[];
+#endif
diff --git a/src/backends/audio/dummy_audio_backend.c b/src/backends/audio/dummy_audio_backend.c
@@ -0,0 +1,45 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ *   Mupen64plus-ui-console - dummy_audio_backend.c                        *
+ *   Mupen64Plus homepage: http://code.google.com/p/mupen64plus/           *
+ *   Copyright (C) 2015 Bobby Smiles                                       *
+ *                                                                         *
+ *   This program 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 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program 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 this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.          *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#include "dummy_audio_backend.h"
+
+#include "m64p_types.h"
+
+#include <string.h>
+
+/* dummy audio backend factory implementation */
+static m64p_error init(struct m64p_audio_backend* backend)
+{
+    /* set to NULL all members to trigger dummy audio backend behavior in the core */
+    memset(backend, 0, sizeof(*backend));
+    return M64ERR_SUCCESS;
+}
+
+static void release(struct m64p_audio_backend* backend)
+{
+}
+
+
+const struct backend_factory dummy_audio_backend_factory =
+{
+    "dummy", init, release
+};
+
diff --git a/src/backends/audio/dummy_audio_backend.h b/src/backends/audio/dummy_audio_backend.h
@@ -0,0 +1,29 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ *   Mupen64plus-ui-console - dummy_audio_backend.h                        *
+ *   Mupen64Plus homepage: http://code.google.com/p/mupen64plus/           *
+ *   Copyright (C) 2015 Bobby Smiles                                       *
+ *                                                                         *
+ *   This program 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 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program 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 this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.          *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#ifndef M64P_DUMMY_AUDIO_BACKEND_H
+#define M64P_DUMMY_AUDIO_BACKEND_H
+
+#include "backend_factory.h"
+
+const struct backend_factory dummy_audio_backend_factory;
+
+#endif
diff --git a/src/backends/audio/sdl_audio_backend.c b/src/backends/audio/sdl_audio_backend.c
@@ -0,0 +1,58 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ *   Mupen64plus-ui-console - sdl_audio_backend.c                          *
+ *   Mupen64Plus homepage: http://code.google.com/p/mupen64plus/           *
+ *   Copyright (C) 2015 Bobby Smiles                                       *
+ *                                                                         *
+ *   This program 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 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program 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 this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.          *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#include "sdl_audio_backend.h"
+
+#include "m64p_types.h"
+#include "main.h"
+
+static void set_audio_format(void* user_data, unsigned int frequency, unsigned int bits)
+{
+    /* TODO implement set audio format */
+    DebugMessage(M64MSG_WARNING, "SDL audio backend set format: %dHz %d bits", frequency, bits);
+
+}
+
+static void push_audio_samples(void* user_data, const void* buffer, size_t size)
+{
+    /* TODO implement push audio samples */
+    DebugMessage(M64MSG_WARNING, "SDL audio backend push samples: @%p  0x%x bytes", buffer, size);
+}
+
+static m64p_error init(struct m64p_audio_backend* backend)
+{
+    /* TODO open SDL audio subsystem */
+
+    /* fill backend structure */
+    backend->user_data = NULL;
+    backend->set_audio_format = set_audio_format;
+    backend->push_audio_samples = push_audio_samples;
+
+    return M64ERR_SUCCESS;
+}
+
+static void release(struct m64p_audio_backend* backend)
+{
+    /* TODO close SDL audio subsystem */
+}
+
+/* SDL audio backend descriptor */
+const struct backend_factory sdl_audio_backend_factory = { "sdl", init, release };
diff --git a/src/backends/audio/sdl_audio_backend.h b/src/backends/audio/sdl_audio_backend.h
@@ -0,0 +1,29 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ *   Mupen64plus-ui-console - sdl_audio_backend.h                          *
+ *   Mupen64Plus homepage: http://code.google.com/p/mupen64plus/           *
+ *   Copyright (C) 2015 Bobby Smiles                                       *
+ *                                                                         *
+ *   This program 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 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program 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 this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.          *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#ifndef M64P_AUDIO_BACKENDS_SDL_AUDIO_BACKEND_H
+#define M64P_AUDIO_BACKENDS_SDL_AUDIO_BACKEND_H
+
+#include "backend_factory.h"
+
+const struct backend_factory sdl_audio_backend_factory;
+
+#endif