It would help if I actually added the output_sdl code, eh?

SVN r1474 (trunk)

output_sdl/CMakeLists.txt

@@ -0,0 +1,8 @@
+cmake_minimum_required( VERSION 2.4 )
+add_library( output_sdl MODULE output_sdl.c )
+include_directories( ${FMOD_INCLUDE_DIR} ${SDL_INCLUDE_DIR} )
+
+FILE( WRITE ${CMAKE_CURRENT_BINARY_DIR}/link-make "if [ ! -e ${ZDOOM_OUTPUT_DIR}/liboutput_sdl.so ]; then ln -sf output_sdl/liboutput_sdl.so ${ZDOOM_OUTPUT_DIR}/liboutput_sdl.so; fi" )
+add_custom_command( TARGET output_sdl POST_BUILD
+	COMMAND chmod +x ${CMAKE_CURRENT_BINARY_DIR}/link-make
+	COMMAND /bin/sh -c ${CMAKE_CURRENT_BINARY_DIR}/link-make )

output_sdl/output_sdl.c

@@ -0,0 +1,215 @@
+#include <stdio.h>
+#include "fmod.h"
+#include "fmod_output.h"
+#include "SDL.h"
+
+#define CONVERTBUFFER_SIZE 	4096	// in bytes
+
+#define D(x)
+
+#define FALSE 	0
+#define TRUE 	1
+
+typedef int BOOL;
+
+struct AudioData
+{
+	FMOD_OUTPUT_STATE *Output;
+	BOOL ConvertU8toS8;
+	BOOL ConvertU16toS16;
+	int BytesPerSample;
+};
+
+FMOD_SOUND_FORMAT Format_SDLtoFMOD(Uint16 format)
+{
+	if ((format & (AUDIO_U8 | AUDIO_U16LSB)) == AUDIO_U8)
+	{
+		return FMOD_SOUND_FORMAT_PCM8;
+	}
+	return FMOD_SOUND_FORMAT_PCM16;
+}
+
+Uint16 Format_FMODtoSDL(FMOD_SOUND_FORMAT format)
+{
+	switch (format)
+	{
+	case FMOD_SOUND_FORMAT_PCM8:	return AUDIO_S8;
+	case FMOD_SOUND_FORMAT_PCM16:	return AUDIO_S16SYS;
+	default: 						return AUDIO_S16SYS;
+	}
+}
+
+static void SDLCALL AudioCallback(void *userdata, Uint8 *stream, int len)
+{
+	struct AudioData *data = (struct AudioData *)userdata;
+	int i;
+
+	data->Output->readfrommixer(data->Output, stream, len / data->BytesPerSample);
+	
+	if (data->ConvertU8toS8)
+	{
+		for (i = 0; i < len; ++i)
+		{
+			stream[i] -= 0x80;
+		}
+	}
+	else if (data->ConvertU16toS16)
+	{
+		len /= 2;
+		for (i = 0; i < len; ++i)
+		{
+			((short *)stream)[i] -= 0x8000;
+		}
+	}
+}
+
+static FMOD_RESULT F_CALLBACK GetNumDrivers(FMOD_OUTPUT_STATE *output_state, int *numdrivers)
+{
+	if (numdrivers == NULL)
+	{
+		return FMOD_ERR_INVALID_PARAM;
+	}
+	*numdrivers = 1;
+	return FMOD_OK;
+}
+
+static FMOD_RESULT F_CALLBACK GetDriverName(FMOD_OUTPUT_STATE *output_state, int id, char *name, int namelen)
+{
+	if (id != 0 || name == NULL)
+	{
+		return FMOD_ERR_INVALID_PARAM;
+	}
+	strncpy(name, "SDL default", namelen);
+	return FMOD_OK;
+}
+
+static FMOD_RESULT F_CALLBACK GetDriverCaps(FMOD_OUTPUT_STATE *output_state, int id, FMOD_CAPS *caps)
+{
+	if (id != 0 || caps == NULL)
+	{
+		return FMOD_ERR_INVALID_PARAM;
+	}
+	*caps = FMOD_CAPS_OUTPUT_FORMAT_PCM8 | FMOD_CAPS_OUTPUT_FORMAT_PCM16 | FMOD_CAPS_OUTPUT_MULTICHANNEL;
+	return FMOD_OK;
+}
+
+static FMOD_RESULT F_CALLBACK Init(FMOD_OUTPUT_STATE *output_state, int selecteddriver,
+	FMOD_INITFLAGS flags, int *outputrate, int outputchannels,
+	FMOD_SOUND_FORMAT *outputformat, int dspbufferlength, int dspnumbuffers,
+	void *extradriverdata)
+{
+	SDL_AudioSpec desired, obtained;
+	struct AudioData *data;
+	
+	if (selecteddriver != 0 || outputrate == NULL || outputformat == NULL)
+	{
+		D(printf("invalid param\n"));
+		return FMOD_ERR_INVALID_PARAM;
+	}
+	if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0)
+	{
+		D(printf("init subsystem failed\n"));
+		return FMOD_ERR_OUTPUT_INIT;
+	}
+	data = malloc(sizeof(*data));
+	if (data == NULL)
+	{
+		D(printf("nomem\n"));
+		SDL_QuitSubSystem(SDL_INIT_AUDIO);
+		return FMOD_ERR_MEMORY;
+	}
+	desired.freq = *outputrate;
+	desired.format = Format_FMODtoSDL(*outputformat);
+	desired.channels = outputchannels;
+	desired.samples = dspbufferlength;
+	desired.callback = AudioCallback;
+	desired.userdata = data;
+	if (SDL_OpenAudio(&desired, &obtained) < 0)
+	{
+		D(printf("openaudio failed\n"));
+		free(data);
+		SDL_QuitSubSystem(SDL_INIT_AUDIO);
+		return FMOD_ERR_OUTPUT_INIT;
+	}
+	if (obtained.channels != outputchannels)
+	{ // Obtained channels don't match what we wanted.
+		SDL_CloseAudio();
+		SDL_QuitSubSystem(SDL_INIT_AUDIO);
+		free(data);
+		return FMOD_ERR_OUTPUT_CREATEBUFFER;
+	}
+	data->Output = output_state;
+	data->ConvertU8toS8 = FALSE;
+	data->ConvertU16toS16 = FALSE;
+	if (obtained.format == AUDIO_U8)
+	{
+		data->ConvertU8toS8 = TRUE;
+		D(printf("convert u8 to s8\n"));
+	}
+	else if (obtained.format == AUDIO_U16SYS)
+	{
+		data->ConvertU16toS16 = TRUE;
+		D(printf("convert u16 to s16\n"));
+	}
+	output_state->plugindata = data;
+	*outputrate = obtained.freq;
+	*outputformat = Format_SDLtoFMOD(obtained.format);
+	data->BytesPerSample = *outputformat == FMOD_SOUND_FORMAT_PCM16 ? 2 : 1;
+	data->BytesPerSample *= desired.channels;
+	D(printf("init ok\n"));
+	SDL_PauseAudio(0);
+	return FMOD_OK;
+}
+
+static FMOD_RESULT F_CALLBACK Close(FMOD_OUTPUT_STATE *output_state)
+{
+	struct AudioData *data = (struct AudioData *)output_state->plugindata;
+	
+	D(printf("Close\n"));
+	if (data != NULL)
+	{
+		SDL_CloseAudio();
+		SDL_QuitSubSystem(SDL_INIT_AUDIO);
+		free(data);
+	}
+	return FMOD_OK;
+}
+
+static FMOD_RESULT F_CALLBACK Update(FMOD_OUTPUT_STATE *update)
+{
+	return FMOD_OK;
+}
+
+static FMOD_RESULT F_CALLBACK GetHandle(FMOD_OUTPUT_STATE *output_state, void **handle)
+{
+	D(printf("Gethandle\n"));
+	// SDL's audio isn't multi-instanced, so this is pretty meaningless
+	if (handle == NULL)
+	{
+		return FMOD_ERR_INVALID_PARAM;
+	}
+	*handle = output_state->plugindata;
+	return FMOD_OK;
+}
+
+static FMOD_OUTPUT_DESCRIPTION Desc =
+{
+	"SDL Output",		// name
+	1,					// version
+	0,					// polling
+	GetNumDrivers,
+	GetDriverName,
+	GetDriverCaps,
+	Init,
+	Close,
+	Update,
+	GetHandle,
+	NULL,				// getposition
+	NULL,				// lock
+	NULL				// unlock
+};
+
+F_DECLSPEC F_DLLEXPORT FMOD_OUTPUT_DESCRIPTION * F_API FMODGetOutputDescription()
+{
+	return &Desc;
+}