SDL_sound_CoreAudio: playsound/playsound.c comparison

comparison playsound/playsound.c @ 270:cf8c0bbbdc19

--volume control.

author	Ryan C. Gordon <icculus@icculus.org>
date	Thu, 07 Mar 2002 09:38:51 +0000
parents	c54eae85f5f1
children	0ac181b5adc6

comparison

equal deleted inserted replaced

-:e11b87a3ec91
+:cf8c0bbbdc19
 *
 *  This file written by Ryan C. Gordon. (icculus@clutteredmind.org)
 */
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <assert.h>
 #include <signal.h>
 #include "SDL.h"
 #include "SDL_sound.h"
 "     --rate n       Playback at sample rate of n HZ.\n"
 "     --format fmt   Playback in fmt format (see below).\n"
 "     --channels n   Playback on n channels (1 or 2).\n"
 "     --decodebuf n  Buffer n decoded bytes at a time (default %d).\n"
 "     --audiobuf n   Buffer n samples to audio device (default %d).\n"
+"     --volume n     Playback volume multiplier (default 1.0).\n"
 "     --version      Display version information and exit.\n"
 "     --decoders     List supported data formats and exit.\n"
 "     --predecode    Decode entire sample before playback.\n"
 "     --loop         Loop playback until SIGINT.\n"
 "     --credits      Shameless promotion.\n"
 static Uint8 *decoded_ptr = NULL;
 static Uint32 decoded_bytes = 0;
 static int predecode = 0;
 static int looping = 0;
+static int wants_volume_change = 0;
+static float volume = 1.0;
 /*
 * This updates (decoded_bytes) and (decoder_ptr) with more audio data,
 *  taking into account looping and/or predecoding.
 */
 assert(0);  /* shouldn't ever hit this point. */
 return(0);
 } /* read_more_data */
+static void memcpy_with_volume(Sound_Sample *sample,
+Uint8 *dst, Uint8 *src, int len)
+{
+int i;
+Uint16 *u16src = NULL;
+Uint16 *u16dst = NULL;
+Sint16 *s16src = NULL;
+Sint16 *s16dst = NULL;
+if (!wants_volume_change)
+{
+memcpy(dst, src, len);
+return;
+}
+/* !!! FIXME: This would be more efficient with a lookup table. */
+switch (sample->desired.format)
+{
+case AUDIO_U8:
+for (i = 0; i < len; i++, src++, dst++)
+*dst = (Uint8) (((float) (*src)) * volume);
+break;
+case AUDIO_S8:
+for (i = 0; i < len; i++, src++, dst++)
+*dst = (Sint8) (((float) (*src)) * volume);
+break;
+case AUDIO_U16LSB:
+u16src = (Uint16 *) src;
+u16dst = (Uint16 *) dst;
+for (i = 0; i < len; i += sizeof (Uint16), u16src++, u16dst++)
+{
+*u16dst = (Uint16) (((float) (SDL_SwapLE16(*u16src))) * volume);
+*u16dst = SDL_SwapLE16(*u16dst);
+}
+break;
+case AUDIO_S16LSB:
+s16src = (Sint16 *) src;
+s16dst = (Sint16 *) dst;
+for (i = 0; i < len; i += sizeof (Sint16), s16src++, s16dst++)
+{
+*s16dst = (Sint16) (((float) (SDL_SwapLE16(*s16src))) * volume);
+*s16dst = SDL_SwapLE16(*s16dst);
+}
+break;
+case AUDIO_U16MSB:
+u16src = (Uint16 *) src;
+u16dst = (Uint16 *) dst;
+for (i = 0; i < len; i += sizeof (Uint16), u16src++, u16dst++)
+{
+*u16dst = (Uint16) (((float) (SDL_SwapBE16(*u16src))) * volume);
+*u16dst = SDL_SwapBE16(*u16dst);
+}
+break;
+case AUDIO_S16MSB:
+s16src = (Sint16 *) src;
+s16dst = (Sint16 *) dst;
+for (i = 0; i < len; i += sizeof (Sint16), s16src++, s16dst++)
+{
+*s16dst = (Sint16) (((float) (SDL_SwapBE16(*s16src))) * volume);
+*s16dst = SDL_SwapBE16(*s16dst);
+}
+break;
+}
+}
 static void audio_callback(void *userdata, Uint8 *stream, int len)
 {
 Sound_Sample *sample = (Sound_Sample *) userdata;
 int bw = 0; /* bytes written to stream this time through the callback */
 if (cpysize > decoded_bytes)
 cpysize = decoded_bytes;
 if (cpysize > 0)
 {
-memcpy(stream + bw, decoded_ptr, cpysize);
+memcpy_with_volume(sample, stream + bw, decoded_ptr, cpysize);
 bw += cpysize;
 decoded_ptr += cpysize;
 decoded_bytes -= cpysize;
 } /* if */
 } /* while */
 else if (strcmp(argv[i], "--decodebuf") == 0 && argc > i + 1)
 {
 decode_buffersize = atoi(argv[++i]);
 } /* else if */
+else if (strcmp(argv[i], "--volume") == 0 && argc > i + 1)
+{
+volume = atof(argv[++i]);
+if (volume != 1.0)
+wants_volume_change = 1;
+} /* else if */
 else if (strcmp(argv[i], "--decoders") == 0)
 {
 if (!Sound_Init())
 {
 fprintf(stderr, "Sound_Init() failed!\n"
 /* !!! FIXME: This is ugly! */
 if ( (strcmp(argv[i], "--rate") == 0) ||
 (strcmp(argv[i], "--format") == 0) ||
 (strcmp(argv[i], "--channels") == 0) ||
 (strcmp(argv[i], "--audiobuf") == 0) ||
-(strcmp(argv[i], "--decodebuf") == 0) )
+(strcmp(argv[i], "--decodebuf") == 0) ||
+(strcmp(argv[i], "--volume") == 0) )
 {
 i++;
 continue;
 } /* if */

Mercurial > SDL_sound_CoreAudio

comparison playsound/playsound.c @ 270:cf8c0bbbdc19