Mercurial > SDL_sound_CoreAudio
diff 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 |
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--- a/playsound/playsound.c Thu Mar 07 09:38:30 2002 +0000 +++ b/playsound/playsound.c Thu Mar 07 09:38:51 2002 +0000 @@ -26,6 +26,7 @@ */ #include <stdio.h> +#include <stdlib.h> #include <string.h> #include <assert.h> #include <signal.h> @@ -106,6 +107,7 @@ " --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" @@ -175,6 +177,8 @@ 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, @@ -219,6 +223,76 @@ } /* 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; @@ -244,7 +318,7 @@ 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; @@ -364,6 +438,13 @@ 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()) @@ -431,7 +512,8 @@ (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;