1 /* Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 * Use of this source code is governed by a BSD-style license that can be 3 * found in the LICENSE file. 4 */ 5 6 /* From ppb_audio_config.idl modified Fri Jan 24 16:19:35 2014. */ 7 8 #ifndef PPAPI_C_PPB_AUDIO_CONFIG_H_ 9 #define PPAPI_C_PPB_AUDIO_CONFIG_H_ 10 11 #include "ppapi/c/pp_bool.h" 12 #include "ppapi/c/pp_instance.h" 13 #include "ppapi/c/pp_macros.h" 14 #include "ppapi/c/pp_resource.h" 15 #include "ppapi/c/pp_stdint.h" 16 17 #define PPB_AUDIO_CONFIG_INTERFACE_1_0 "PPB_AudioConfig;1.0" 18 #define PPB_AUDIO_CONFIG_INTERFACE_1_1 "PPB_AudioConfig;1.1" 19 #define PPB_AUDIO_CONFIG_INTERFACE PPB_AUDIO_CONFIG_INTERFACE_1_1 20 21 /** 22 * @file 23 * This file defines the PPB_AudioConfig interface for establishing an 24 * audio configuration resource within the browser. 25 */ 26 27 28 /** 29 * @addtogroup Enums 30 * @{ 31 */ 32 /** 33 * This enumeration contains audio frame count constants. 34 * <code>PP_AUDIOMINSAMPLEFRAMECOUNT</code> is the minimum possible frame 35 * count. <code>PP_AUDIOMAXSAMPLEFRAMECOUNT</code> is the maximum possible 36 * frame count. 37 */ 38 enum { 39 PP_AUDIOMINSAMPLEFRAMECOUNT = 64, 40 PP_AUDIOMAXSAMPLEFRAMECOUNT = 32768 41 }; 42 43 /** 44 * PP_AudioSampleRate is an enumeration of the different audio sampling rates. 45 * <code>PP_AUDIOSAMPLERATE_44100</code> is the sample rate used on CDs and 46 * <code>PP_AUDIOSAMPLERATE_48000</code> is the sample rate used on DVDs and 47 * Digital Audio Tapes. 48 */ 49 typedef enum { 50 PP_AUDIOSAMPLERATE_NONE = 0, 51 PP_AUDIOSAMPLERATE_44100 = 44100, 52 PP_AUDIOSAMPLERATE_48000 = 48000 53 } PP_AudioSampleRate; 54 PP_COMPILE_ASSERT_SIZE_IN_BYTES(PP_AudioSampleRate, 4); 55 /** 56 * @} 57 */ 58 59 /** 60 * @addtogroup Interfaces 61 * @{ 62 */ 63 /** 64 * The <code>PPB_AudioConfig</code> interface contains pointers to several 65 * functions for establishing your audio configuration within the browser. 66 * This interface only supports 16-bit stereo output. 67 * 68 * Refer to the 69 * <a href="/native-client/devguide/coding/audio.html">Audio 70 * </a> chapter in the Developer's Guide for information on using this 71 * interface. 72 */ 73 struct PPB_AudioConfig_1_1 { 74 /** 75 * CreateStereo16bit() creates a 16 bit audio configuration resource. The 76 * <code>sample_rate</code> should be the result of calling 77 * <code>RecommendSampleRate</code> and <code>sample_frame_count</code> should 78 * be the result of calling <code>RecommendSampleFrameCount</code>. If the 79 * sample frame count or bit rate isn't supported, this function will fail and 80 * return a null resource. 81 * 82 * A single sample frame on a stereo device means one value for the left 83 * channel and one value for the right channel. 84 * 85 * Buffer layout for a stereo int16 configuration: 86 * <code>int16_t *buffer16;</code> 87 * <code>buffer16[0]</code> is the first left channel sample. 88 * <code>buffer16[1]</code> is the first right channel sample. 89 * <code>buffer16[2]</code> is the second left channel sample. 90 * <code>buffer16[3]</code> is the second right channel sample. 91 * ... 92 * <code>buffer16[2 * (sample_frame_count - 1)]</code> is the last left 93 * channel sample. 94 * <code>buffer16[2 * (sample_frame_count - 1) + 1]</code> is the last 95 * right channel sample. 96 * Data will always be in the native endian format of the platform. 97 * 98 * @param[in] instance A <code>PP_Instance</code> identifying one instance 99 * of a module. 100 * @param[in] sample_rate A <code>PP_AudioSampleRate</code> which is either 101 * <code>PP_AUDIOSAMPLERATE_44100</code> or 102 * <code>PP_AUDIOSAMPLERATE_48000</code>. 103 * @param[in] sample_frame_count A <code>uint32_t</code> frame count returned 104 * from the <code>RecommendSampleFrameCount</code> function. 105 * 106 * @return A <code>PP_Resource</code> containing the 107 * <code>PPB_Audio_Config</code> if successful or a null resource if the 108 * sample frame count or bit rate are not supported. 109 */ 110 PP_Resource (*CreateStereo16Bit)(PP_Instance instance, 111 PP_AudioSampleRate sample_rate, 112 uint32_t sample_frame_count); 113 /** 114 * RecommendSampleFrameCount() returns the supported sample frame count 115 * closest to the requested count. The sample frame count determines the 116 * overall latency of audio. Since one "frame" is always buffered in advance, 117 * smaller frame counts will yield lower latency, but higher CPU utilization. 118 * 119 * Supported sample frame counts will vary by hardware and system (consider 120 * that the local system might be anywhere from a cell phone or a high-end 121 * audio workstation). Sample counts less than 122 * <code>PP_AUDIOMINSAMPLEFRAMECOUNT</code> and greater than 123 * <code>PP_AUDIOMAXSAMPLEFRAMECOUNT</code> are never supported on any 124 * system, but values in between aren't necessarily valid. This function 125 * will return a supported count closest to the requested frame count. 126 * 127 * RecommendSampleFrameCount() result is intended for audio output devices. 128 * 129 * @param[in] instance 130 * @param[in] sample_rate A <code>PP_AudioSampleRate</code> which is either 131 * <code>PP_AUDIOSAMPLERATE_44100</code> or 132 * <code>PP_AUDIOSAMPLERATE_48000.</code> 133 * @param[in] requested_sample_frame_count A <code>uint_32t</code> requested 134 * frame count. 135 * 136 * @return A <code>uint32_t</code> containing the recommended sample frame 137 * count if successful. 138 */ 139 uint32_t (*RecommendSampleFrameCount)( 140 PP_Instance instance, 141 PP_AudioSampleRate sample_rate, 142 uint32_t requested_sample_frame_count); 143 /** 144 * IsAudioConfig() determines if the given resource is a 145 * <code>PPB_Audio_Config</code>. 146 * 147 * @param[in] resource A <code>PP_Resource</code> corresponding to an audio 148 * config resource. 149 * 150 * @return A <code>PP_Bool</code> containing <code>PP_TRUE</code> if the given 151 * resource is an <code>AudioConfig</code> resource, otherwise 152 * <code>PP_FALSE</code>. 153 */ 154 PP_Bool (*IsAudioConfig)(PP_Resource resource); 155 /** 156 * GetSampleRate() returns the sample rate for the given 157 * <code>PPB_Audio_Config</code>. 158 * 159 * @param[in] config A <code>PP_Resource</code> corresponding to a 160 * <code>PPB_Audio_Config</code>. 161 * 162 * @return A <code>PP_AudioSampleRate</code> containing sample rate or 163 * <code>PP_AUDIOSAMPLERATE_NONE</code> if the resource is invalid. 164 */ 165 PP_AudioSampleRate (*GetSampleRate)(PP_Resource config); 166 /** 167 * GetSampleFrameCount() returns the sample frame count for the given 168 * <code>PPB_Audio_Config</code>. 169 * 170 * @param[in] config A <code>PP_Resource</code> corresponding to an audio 171 * config resource. 172 * 173 * @return A <code>uint32_t</code> containing sample frame count or 174 * 0 if the resource is invalid. Refer to 175 * RecommendSampleFrameCount() for more on sample frame counts. 176 */ 177 uint32_t (*GetSampleFrameCount)(PP_Resource config); 178 /** 179 * RecommendSampleRate() returns the native sample rate that the browser 180 * is using in the backend. Applications that use the recommended sample 181 * rate will have potentially better latency and fidelity. The return value 182 * is intended for audio output devices. If the output sample rate cannot be 183 * determined, this function can return PP_AUDIOSAMPLERATE_NONE. 184 * 185 * @param[in] instance 186 * 187 * @return A <code>uint32_t</code> containing the recommended sample frame 188 * count if successful. 189 */ 190 PP_AudioSampleRate (*RecommendSampleRate)(PP_Instance instance); 191 }; 192 193 typedef struct PPB_AudioConfig_1_1 PPB_AudioConfig; 194 195 struct PPB_AudioConfig_1_0 { 196 PP_Resource (*CreateStereo16Bit)(PP_Instance instance, 197 PP_AudioSampleRate sample_rate, 198 uint32_t sample_frame_count); 199 uint32_t (*RecommendSampleFrameCount)( 200 PP_AudioSampleRate sample_rate, 201 uint32_t requested_sample_frame_count); 202 PP_Bool (*IsAudioConfig)(PP_Resource resource); 203 PP_AudioSampleRate (*GetSampleRate)(PP_Resource config); 204 uint32_t (*GetSampleFrameCount)(PP_Resource config); 205 }; 206 /** 207 * @} 208 */ 209 210 #endif /* PPAPI_C_PPB_AUDIO_CONFIG_H_ */ 211 212
