src/audio/disk/SDL_diskaudio.c
changeset 68 ac6645260d31
child 86 13e4c612098d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/audio/disk/SDL_diskaudio.c	Sat Jun 16 01:51:42 2001 +0000
@@ -0,0 +1,222 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997, 1998, 1999, 2000, 2001  Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+
+    This library 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
+    Library General Public License for more details.
+
+    You should have received a copy of the GNU Library General Public
+    License along with this library; if not, write to the Free
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+    Sam Lantinga
+    slouken@devolution.com
+
+    This file hacked^H^H^H^H^H^Hwritten by Ryan C. Gordon
+        (icculus@linuxgames.com)
+*/
+
+#ifdef SAVE_RCSID
+static char rcsid =
+ "@(#) $Id$";
+#endif
+
+/* Output raw audio data to a file. */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+
+#include "SDL_audio.h"
+#include "SDL_error.h"
+#include "SDL_audiomem.h"
+#include "SDL_audio_c.h"
+#include "SDL_timer.h"
+#include "SDL_audiodev_c.h"
+#include "SDL_diskaudio.h"
+
+/* The tag name used by DISK audio */
+#define DISKAUD_DRIVER_NAME         "disk"
+
+/* environment variables and defaults. */
+#define DISKENVR_OUTFILE         "SDL_DISKAUDIOFILE"
+#define DISKDEFAULT_OUTFILE      "sdlaudio.raw"
+#define DISKENVR_WRITEDELAY      "SDL_DISKAUDIODELAY"
+#define DISKDEFAULT_WRITEDELAY   150
+
+/* Audio driver functions */
+static int DISKAUD_OpenAudio(_THIS, SDL_AudioSpec *spec);
+static void DISKAUD_WaitAudio(_THIS);
+static void DISKAUD_PlayAudio(_THIS);
+static Uint8 *DISKAUD_GetAudioBuf(_THIS);
+static void DISKAUD_CloseAudio(_THIS);
+
+static const char *DISKAUD_GetOutputFilename(void)
+{
+    const char *envr = getenv(DISKENVR_OUTFILE);
+    return((envr != NULL) ? envr : DISKDEFAULT_OUTFILE);
+}
+
+/* Audio driver bootstrap functions */
+static int DISKAUD_Available(void)
+{
+#if 0
+    int fd;
+	int available;
+    int exists = 0;
+    struct stat statbuf;
+    const char *fname = DISKAUD_GetOutputFilename();
+
+	available = 0;
+
+    if (stat(fname, &statbuf) == 0)
+        exists = 1;
+
+    fd = open(fname, O_WRONLY | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR);
+	if ( fd != -1 ) {
+		available = 1;
+		close(fd);
+        if (!exists) {
+            unlink(fname);
+        }
+	}
+	return(available);
+#else
+    return(1);
+#endif
+}
+
+static void DISKAUD_DeleteDevice(SDL_AudioDevice *device)
+{
+	free(device->hidden);
+	free(device);
+}
+
+static SDL_AudioDevice *DISKAUD_CreateDevice(int devindex)
+{
+	SDL_AudioDevice *this;
+    const char *envr;
+
+	/* Initialize all variables that we clean on shutdown */
+	this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice));
+	if ( this ) {
+		memset(this, 0, (sizeof *this));
+		this->hidden = (struct SDL_PrivateAudioData *)
+				malloc((sizeof *this->hidden));
+	}
+	if ( (this == NULL) || (this->hidden == NULL) ) {
+		SDL_OutOfMemory();
+		if ( this ) {
+			free(this);
+		}
+		return(0);
+	}
+	memset(this->hidden, 0, (sizeof *this->hidden));
+
+    envr = getenv(DISKENVR_WRITEDELAY);
+    this->hidden->write_delay = (envr) ? atoi(envr) : DISKDEFAULT_WRITEDELAY;
+
+	/* Set the function pointers */
+	this->OpenAudio = DISKAUD_OpenAudio;
+	this->WaitAudio = DISKAUD_WaitAudio;
+	this->PlayAudio = DISKAUD_PlayAudio;
+	this->GetAudioBuf = DISKAUD_GetAudioBuf;
+	this->CloseAudio = DISKAUD_CloseAudio;
+
+	this->free = DISKAUD_DeleteDevice;
+
+	return this;
+}
+
+AudioBootStrap DISKAUD_bootstrap = {
+	DISKAUD_DRIVER_NAME, "direct-to-disk audio",
+	DISKAUD_Available, DISKAUD_CreateDevice
+};
+
+/* This function waits until it is possible to write a full sound buffer */
+static void DISKAUD_WaitAudio(_THIS)
+{
+    SDL_Delay(this->hidden->write_delay);
+}
+
+static void DISKAUD_PlayAudio(_THIS)
+{
+	int written;
+
+	/* Write the audio data, checking for EAGAIN on broken audio drivers */
+	do {
+		written = write(this->hidden->audio_fd,
+                        this->hidden->mixbuf,
+                        this->hidden->mixlen);
+		if ( (written < 0) && ((errno == 0) || (errno == EAGAIN)) ) {
+			SDL_Delay(1);	/* Let a little CPU time go by */
+		}
+	} while ( (written < 0) && 
+	          ((errno == 0) || (errno == EAGAIN) || (errno == EINTR)) );
+
+	/* If we couldn't write, assume fatal error for now */
+	if ( written < 0 ) {
+		this->enabled = 0;
+	}
+#ifdef DEBUG_AUDIO
+	fprintf(stderr, "Wrote %d bytes of audio data\n", written);
+#endif
+}
+
+static Uint8 *DISKAUD_GetAudioBuf(_THIS)
+{
+	return(this->hidden->mixbuf);
+}
+
+static void DISKAUD_CloseAudio(_THIS)
+{
+	if ( this->hidden->mixbuf != NULL ) {
+		SDL_FreeAudioMem(this->hidden->mixbuf);
+		this->hidden->mixbuf = NULL;
+	}
+	if ( this->hidden->audio_fd >= 0 ) {
+		close(this->hidden->audio_fd);
+		this->hidden->audio_fd = -1;
+	}
+}
+
+static int DISKAUD_OpenAudio(_THIS, SDL_AudioSpec *spec)
+{
+    const char *fname = DISKAUD_GetOutputFilename();
+
+	/* Open the audio device */
+    this->hidden->audio_fd = open(fname, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
+	if ( this->hidden->audio_fd < 0 ) {
+		SDL_SetError("Couldn't open %s: %s", fname, strerror(errno));
+		return(-1);
+	}
+
+    fprintf(stderr, "WARNING: You are using the SDL disk writer"
+                    " audio driver!\n Writing to file [%s].\n", fname);
+
+	/* Allocate mixing buffer */
+	this->hidden->mixlen = spec->size;
+	this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen);
+	if ( this->hidden->mixbuf == NULL ) {
+		return(-1);
+	}
+	memset(this->hidden->mixbuf, spec->silence, spec->size);
+
+	/* We're ready to rock and roll. :-) */
+	return(0);
+}
+