SSRC.h revision 7c9d8018755adf1857571125ba1b3598c96ea506
1/* 2 * Copyright (C) 2004-2011 NXP Software 3 * Copyright (C) 2011 The Android Open Source Project 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18/****************************************************************************************/ 19/* */ 20/* Project:: */ 21/* %name: SSRC.h % */ 22/* */ 23/****************************************************************************************/ 24 25/* 26 The input and output blocks of the SRC are by default blocks of 40 ms. This means that 27 the following default block sizes are used: 28 29 Fs Default Block size 30 ----- ---------- 31 8000 320 32 11025 441 33 12000 480 34 16000 640 35 22050 882 36 24000 960 37 32000 1280 38 44100 1764 39 48000 1920 40 41 An API is provided to change the default block size into any multiple of the minimal 42 block size. 43 44 All the sampling rates above are supported as input and as output sampling rate 45*/ 46 47#ifndef __SSRC_H__ 48#define __SSRC_H__ 49 50/**************************************************************************************** 51 INCLUDES 52*****************************************************************************************/ 53 54#include "LVM_Types.h" 55 56/**************************************************************************************** 57 DEFINITIONS 58*****************************************************************************************/ 59 60#define SSRC_INSTANCE_SIZE 548 61#define SSRC_INSTANCE_ALIGNMENT 4 62#define SSRC_SCRATCH_ALIGNMENT 4 63 64/**************************************************************************************** 65 TYPE DEFINITIONS 66*****************************************************************************************/ 67 68/* Status return values */ 69typedef enum 70{ 71 SSRC_OK = 0, /* Successful return from a routine */ 72 SSRC_INVALID_FS = 1, /* The input or the output sampling rate is 73 invalid */ 74 SSRC_INVALID_NR_CHANNELS = 2, /* The number of channels is not equal to mono 75 or stereo */ 76 SSRC_NULL_POINTER = 3, /* One of the input pointers is NULL */ 77 SSRC_WRONG_NR_SAMPLES = 4, /* Invalid number of samples */ 78 SSRC_ALLINGMENT_ERROR = 5, /* The instance memory or the scratch memory 79 is not alligned */ 80 SSRC_INVALID_MODE = 6, /* A wrong value has been used for the mode 81 parameter */ 82 SSRC_INVALID_VALUE = 7, /* An invalid (out of range) value has been 83 used for one of the parameters */ 84 LVXXX_RETURNSTATUS_DUMMY = LVM_MAXENUM 85} SSRC_ReturnStatus_en; 86 87/* Instance memory */ 88typedef struct 89{ 90 LVM_INT32 Storage [ SSRC_INSTANCE_SIZE/4 ]; 91} SSRC_Instance_t; 92 93/* Scratch memory */ 94typedef LVM_INT32 SSRC_Scratch_t; 95 96/* Nuber of samples mode */ 97typedef enum 98{ 99 SSRC_NR_SAMPLES_DEFAULT = 0, 100 SSRC_NR_SAMPLES_MIN = 1, 101 SSRC_NR_SAMPLES_DUMMY = LVM_MAXENUM 102} SSRC_NR_SAMPLES_MODE_en; 103 104/* Instance parameters */ 105typedef struct 106{ 107 LVM_Fs_en SSRC_Fs_In; 108 LVM_Fs_en SSRC_Fs_Out; 109 LVM_Format_en SSRC_NrOfChannels; 110 LVM_INT16 NrSamplesIn; 111 LVM_INT16 NrSamplesOut; 112} SSRC_Params_t; 113 114 115/**************************************************************************************** 116 FUNCTION PROTOTYPES 117*****************************************************************************************/ 118 119 120/****************************************************************************************/ 121/* */ 122/* FUNCTION: SSRC_GetNrSamples */ 123/* */ 124/* DESCRIPTION: */ 125/* This function retrieves the number of samples (or sample pairs for stereo) to be */ 126/* used as input and as output of the SSRC module. */ 127/* */ 128/* PARAMETERS: */ 129/* Mode There are two modes: */ 130/* - SSRC_NR_SAMPELS_DEFAULT. In this mode, the function */ 131/* will return the number of samples for 40 ms blocks */ 132/* - SSRC_NR_SAMPELS_MIN will return the minimal number */ 133/* of samples that is supported for this conversion */ 134/* ratio. Each integer multiple of this ratio will */ 135/* be accepted by the SSRC_Init function */ 136/* */ 137/* pSSRC_Params pointer to the instance parameters */ 138/* */ 139/* RETURNS: */ 140/* SSRC_OK Succeeded */ 141/* SSRC_INVALID_FS When the requested input or output sampling rates */ 142/* are invalid. */ 143/* SSRC_INVALID_NR_CHANNELS When the channel format is not equal to LVM_MONO */ 144/* or LVM_STEREO */ 145/* SSRC_NULL_POINTER When pSSRC_Params is a NULL pointer */ 146/* SSRC_INVALID_MODE When Mode is not a valid setting */ 147/* */ 148/* */ 149/* NOTES: */ 150/* */ 151/****************************************************************************************/ 152 153SSRC_ReturnStatus_en SSRC_GetNrSamples( SSRC_NR_SAMPLES_MODE_en Mode, 154 SSRC_Params_t* pSSRC_Params ); 155 156 157/****************************************************************************************/ 158/* */ 159/* FUNCTION: SSRC_GetScratchSize */ 160/* */ 161/* DESCRIPTION: */ 162/* This function retrieves the scratch size for a given conversion ratio and */ 163/* for given buffer sizes at the input and at the output */ 164/* */ 165/* PARAMETERS: */ 166/* pSSRC_Params pointer to the instance parameters */ 167/* pScratchSize pointer to the scratch size. The SSRC_GetScratchSize */ 168/* function will fill in the correct value (in bytes). */ 169/* */ 170/* RETURNS: */ 171/* SSRC_OK when the function call succeeds */ 172/* SSRC_INVALID_FS When the requested input or output sampling rates */ 173/* are invalid. */ 174/* SSRC_INVALID_NR_CHANNELS When the channel format is not equal to LVM_MONO */ 175/* or LVM_STEREO */ 176/* SSRC_NULL_POINTER When any of the input pointers is a NULL pointer */ 177/* SSRC_WRONG_NR_SAMPLES When the number of samples on the input or on the output */ 178/* are incorrect */ 179/* */ 180/* NOTES: */ 181/* */ 182/****************************************************************************************/ 183 184SSRC_ReturnStatus_en SSRC_GetScratchSize( SSRC_Params_t* pSSRC_Params, 185 LVM_INT32* pScratchSize ); 186 187 188/****************************************************************************************/ 189/* */ 190/* FUNCTION: SSRC_Init */ 191/* */ 192/* DESCRIPTION: */ 193/* This function is used to initialize the SSRC module instance. */ 194/* */ 195/* PARAMETERS: */ 196/* pSSRC_Instance Instance pointer */ 197/* */ 198/* pSSRC_Scratch pointer to the scratch memory */ 199/* pSSRC_Params pointer to the instance parameters */ 200/* pInputInScratch, pointer to a location in the scratch memory that can be */ 201/* used to store the input samples (e.g. to save memory) */ 202/* pOutputInScratch pointer to a location in the scratch memory that can be */ 203/* used to store the output samples (e.g. to save memory) */ 204/* */ 205/* RETURNS: */ 206/* SSRC_OK Succeeded */ 207/* SSRC_INVALID_FS When the requested input or output sampling rates */ 208/* are invalid. */ 209/* SSRC_INVALID_NR_CHANNELS When the channel format is not equal to LVM_MONO */ 210/* or LVM_STEREO */ 211/* SSRC_WRONG_NR_SAMPLES When the number of samples on the input or the output */ 212/* are incorrect */ 213/* SSRC_NULL_POINTER When any of the input pointers is a NULL pointer */ 214/* SSRC_ALLINGMENT_ERROR When the instance memory or the scratch memory is not */ 215/* 4 bytes alligned */ 216/* */ 217/* NOTES: */ 218/* 1. The init function will clear the internal state */ 219/* */ 220/****************************************************************************************/ 221 222SSRC_ReturnStatus_en SSRC_Init( SSRC_Instance_t* pSSRC_Instance, 223 SSRC_Scratch_t* pSSRC_Scratch, 224 SSRC_Params_t* pSSRC_Params, 225 LVM_INT16** ppInputInScratch, 226 LVM_INT16** ppOutputInScratch); 227 228 229/****************************************************************************************/ 230/* */ 231/* FUNCTION: SSRC_SetGains */ 232/* */ 233/* DESCRIPTION: */ 234/* This function sets headroom gain and the post gain of the SSRC */ 235/* */ 236/* PARAMETERS: */ 237/* bHeadroomGainEnabled parameter to enable or disable the headroom gain of the */ 238/* SSRC. The default value is LVM_MODE_ON. LVM_MODE_OFF */ 239/* can be used in case it can be guaranteed that the input */ 240/* level is below -6dB in all cases (the default headroom */ 241/* is -6 dB) */ 242/* */ 243/* bOutputGainEnabled parameter to enable or disable the output gain. The */ 244/* default value is LVM_MODE_ON */ 245/* */ 246/* OutputGain the value of the output gain. The output gain is a linear */ 247/* gain value. 0x7FFF is equal to +6 dB and 0x0000 corresponds */ 248/* to -inf dB. By default, a 3dB gain is applied, resulting */ 249/* in an overall gain of -3dB (-6dB headroom + 3dB output gain)*/ 250/* */ 251/* RETURNS: */ 252/* SSRC_OK Succeeded */ 253/* SSRC_NULL_POINTER When pSSRC_Instance is a NULL pointer */ 254/* SSRC_INVALID_MODE Wrong value used for the bHeadroomGainEnabled or the */ 255/* bOutputGainEnabled parameters. */ 256/* SSRC_INVALID_VALUE When OutputGain is out to the range [0;32767] */ 257/* */ 258/* NOTES: */ 259/* 1. The SSRC_SetGains function is an optional function that should only be used */ 260/* in rare cases. Preferably, use the default settings. */ 261/* */ 262/****************************************************************************************/ 263 264SSRC_ReturnStatus_en SSRC_SetGains( SSRC_Instance_t* pSSRC_Instance, 265 LVM_Mode_en bHeadroomGainEnabled, 266 LVM_Mode_en bOutputGainEnabled, 267 LVM_INT16 OutputGain ); 268 269 270/****************************************************************************************/ 271/* */ 272/* FUNCTION: SSRC_Process */ 273/* */ 274/* DESCRIPTION: */ 275/* Process function for the SSRC module. */ 276/* */ 277/* PARAMETERS: */ 278/* pSSRC_Instance Instance pointer */ 279/* pSSRC_AudioIn Pointer to the input data */ 280/* pSSRC_AudioOut Pointer to the output data */ 281/* */ 282/* RETURNS: */ 283/* SSRC_OK Succeeded */ 284/* SSRC_NULL_POINTER When one of pSSRC_Instance, pSSRC_AudioIn or pSSRC_AudioOut */ 285/* is NULL */ 286/* */ 287/* NOTES: */ 288/* */ 289/****************************************************************************************/ 290 291SSRC_ReturnStatus_en SSRC_Process( SSRC_Instance_t* pSSRC_Instance, 292 LVM_INT16* pSSRC_AudioIn, 293 LVM_INT16* pSSRC_AudioOut); 294 295/****************************************************************************************/ 296 297#endif /* __SSRC_H__ */ 298