#include <stdio.h> #include "SDL_audio.h" #include "SDL_byteorder.h" #include "quakedef.h" static dma_t the_shm; static int snd_inited; extern int desired_speed; extern int desired_bits; static void paint_audio(void *unused, Uint8 *stream, int len) { if ( shm ) { shm->buffer = stream; shm->samplepos += len/(shm->samplebits/8)/2; // Check for samplepos overflow? S_PaintChannels (shm->samplepos); } } qboolean SNDDMA_Init(void) { SDL_AudioSpec desired, obtained; snd_inited = 0; /* Set up the desired format */ desired.freq = desired_speed; switch (desired_bits) { case 8: desired.format = AUDIO_U8; break; case 16: if ( SDL_BYTEORDER == SDL_BIG_ENDIAN ) desired.format = AUDIO_S16MSB; else desired.format = AUDIO_S16LSB; break; default: Con_Printf("Unknown number of audio bits: %d\n", desired_bits); return 0; } desired.channels = 2; desired.samples = 512; desired.callback = paint_audio; /* Open the audio device */ if ( SDL_OpenAudio(&desired, &obtained) < 0 ) { Con_Printf("Couldn't open SDL audio: %s\n", SDL_GetError()); return 0; } /* Make sure we can support the audio format */ switch (obtained.format) { case AUDIO_U8: /* Supported */ break; case AUDIO_S16LSB: case AUDIO_S16MSB: if ( ((obtained.format == AUDIO_S16LSB) && (SDL_BYTEORDER == SDL_LIL_ENDIAN)) || ((obtained.format == AUDIO_S16MSB) && (SDL_BYTEORDER == SDL_BIG_ENDIAN)) ) { /* Supported */ break; } /* Unsupported, fall through */; default: /* Not supported -- force SDL to do our bidding */ SDL_CloseAudio(); if ( SDL_OpenAudio(&desired, NULL) < 0 ) { Con_Printf("Couldn't open SDL audio: %s\n", SDL_GetError()); return 0; } memcpy(&obtained, &desired, sizeof(desired)); break; } SDL_PauseAudio(0); /* Fill the audio DMA information block */ shm = &the_shm; shm->splitbuffer = 0; shm->samplebits = (obtained.format & 0xFF); shm->speed = obtained.freq; shm->channels = obtained.channels; shm->samples = obtained.samples*shm->channels; shm->samplepos = 0; shm->submission_chunk = 1; shm->buffer = NULL; snd_inited = 1; return 1; } int SNDDMA_GetDMAPos(void) { return shm->samplepos; } void SNDDMA_Shutdown(void) { if (snd_inited) { SDL_CloseAudio(); snd_inited = 0; } }