1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /** \file SDL.c SDL platform implementation */ 18 19 #include "sles_allinclusive.h" 20 21 22 /** \brief Called by SDL to fill the next audio output buffer */ 23 24 static void SDLCALL SDL_callback(void *context, Uint8 *stream, int len) 25 { 26 assert(len > 0); 27 IEngine *thisEngine = (IEngine *) context; 28 // A peek lock would be risky if output mixes are dynamic, so we use SDL_PauseAudio to 29 // temporarily disable callbacks during any change to the current output mix, and use a 30 // shared lock here 31 interface_lock_shared(thisEngine); 32 COutputMix *outputMix = thisEngine->mOutputMix; 33 interface_unlock_shared(thisEngine); 34 if (NULL != outputMix) { 35 SLOutputMixExtItf OutputMixExt = &outputMix->mOutputMixExt.mItf; 36 IOutputMixExt_FillBuffer(OutputMixExt, stream, (SLuint32) len); 37 } else { 38 memset(stream, 0, (size_t) len); 39 } 40 } 41 42 43 /** \brief Called during slCreateEngine to initialize SDL */ 44 45 void SDL_open(IEngine *thisEngine) 46 { 47 SDL_AudioSpec fmt; 48 fmt.freq = 44100; 49 fmt.format = AUDIO_S16; 50 fmt.channels = STEREO_CHANNELS; 51 #ifdef _WIN32 // FIXME Either a bug or a serious misunderstanding 52 fmt.samples = SndFile_BUFSIZE; 53 #else 54 fmt.samples = SndFile_BUFSIZE / sizeof(short); 55 #endif 56 fmt.callback = SDL_callback; 57 fmt.userdata = (void *) thisEngine; 58 59 if (SDL_OpenAudio(&fmt, NULL) < 0) { 60 SL_LOGE("Unable to open audio: %s", SDL_GetError()); 61 exit(EXIT_FAILURE); 62 } 63 } 64 65 66 /** \brief Called during Object::Destroy for engine to shutdown SDL */ 67 68 void SDL_close(void) 69 { 70 SDL_CloseAudio(); 71 } 72
