| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /****************************************************************************************/ |
| /* */ |
| /* Project:: */ |
| /* %name: SSRC.h % */ |
| /* */ |
| /****************************************************************************************/ |
| |
| /* |
| The input and output blocks of the SRC are by default blocks of 40 ms. This means that |
| the following default block sizes are used: |
| |
| Fs Default Block size |
| ----- ---------- |
| 8000 320 |
| 11025 441 |
| 12000 480 |
| 16000 640 |
| 22050 882 |
| 24000 960 |
| 32000 1280 |
| 44100 1764 |
| 48000 1920 |
| |
| An API is provided to change the default block size into any multiple of the minimal |
| block size. |
| |
| All the sampling rates above are supported as input and as output sampling rate |
| */ |
| |
| #ifndef __SSRC_H__ |
| #define __SSRC_H__ |
| |
| /**************************************************************************************** |
| INCLUDES |
| *****************************************************************************************/ |
| |
| #include "LVM_Types.h" |
| |
| /**************************************************************************************** |
| DEFINITIONS |
| *****************************************************************************************/ |
| |
| #define SSRC_INSTANCE_SIZE 548 |
| #define SSRC_INSTANCE_ALIGNMENT 4 |
| #define SSRC_SCRATCH_ALIGNMENT 4 |
| |
| /**************************************************************************************** |
| TYPE DEFINITIONS |
| *****************************************************************************************/ |
| |
| /* Status return values */ |
| typedef enum |
| { |
| SSRC_OK = 0, /* Successful return from a routine */ |
| SSRC_INVALID_FS = 1, /* The input or the output sampling rate is |
| invalid */ |
| SSRC_INVALID_NR_CHANNELS = 2, /* The number of channels is not equal to mono |
| or stereo */ |
| SSRC_NULL_POINTER = 3, /* One of the input pointers is NULL */ |
| SSRC_WRONG_NR_SAMPLES = 4, /* Invalid number of samples */ |
| SSRC_ALLINGMENT_ERROR = 5, /* The instance memory or the scratch memory |
| is not alligned */ |
| SSRC_INVALID_MODE = 6, /* A wrong value has been used for the mode |
| parameter */ |
| SSRC_INVALID_VALUE = 7, /* An invalid (out of range) value has been |
| used for one of the parameters */ |
| LVXXX_RETURNSTATUS_DUMMY = LVM_MAXENUM |
| } SSRC_ReturnStatus_en; |
| |
| /* Instance memory */ |
| typedef struct |
| { |
| LVM_INT32 Storage [ SSRC_INSTANCE_SIZE/4 ]; |
| } SSRC_Instance_t; |
| |
| /* Scratch memory */ |
| typedef LVM_INT32 SSRC_Scratch_t; |
| |
| /* Nuber of samples mode */ |
| typedef enum |
| { |
| SSRC_NR_SAMPLES_DEFAULT = 0, |
| SSRC_NR_SAMPLES_MIN = 1, |
| SSRC_NR_SAMPLES_DUMMY = LVM_MAXENUM |
| } SSRC_NR_SAMPLES_MODE_en; |
| |
| /* Instance parameters */ |
| typedef struct |
| { |
| LVM_Fs_en SSRC_Fs_In; |
| LVM_Fs_en SSRC_Fs_Out; |
| LVM_Format_en SSRC_NrOfChannels; |
| LVM_INT16 NrSamplesIn; |
| LVM_INT16 NrSamplesOut; |
| } SSRC_Params_t; |
| |
| |
| /**************************************************************************************** |
| FUNCTION PROTOTYPES |
| *****************************************************************************************/ |
| |
| |
| /****************************************************************************************/ |
| /* */ |
| /* FUNCTION: SSRC_GetNrSamples */ |
| /* */ |
| /* DESCRIPTION: */ |
| /* This function retrieves the number of samples (or sample pairs for stereo) to be */ |
| /* used as input and as output of the SSRC module. */ |
| /* */ |
| /* PARAMETERS: */ |
| /* Mode There are two modes: */ |
| /* - SSRC_NR_SAMPELS_DEFAULT. In this mode, the function */ |
| /* will return the number of samples for 40 ms blocks */ |
| /* - SSRC_NR_SAMPELS_MIN will return the minimal number */ |
| /* of samples that is supported for this conversion */ |
| /* ratio. Each integer multiple of this ratio will */ |
| /* be accepted by the SSRC_Init function */ |
| /* */ |
| /* pSSRC_Params pointer to the instance parameters */ |
| /* */ |
| /* RETURNS: */ |
| /* SSRC_OK Succeeded */ |
| /* SSRC_INVALID_FS When the requested input or output sampling rates */ |
| /* are invalid. */ |
| /* SSRC_INVALID_NR_CHANNELS When the channel format is not equal to LVM_MONO */ |
| /* or LVM_STEREO */ |
| /* SSRC_NULL_POINTER When pSSRC_Params is a NULL pointer */ |
| /* SSRC_INVALID_MODE When Mode is not a valid setting */ |
| /* */ |
| /* */ |
| /* NOTES: */ |
| /* */ |
| /****************************************************************************************/ |
| |
| SSRC_ReturnStatus_en SSRC_GetNrSamples( SSRC_NR_SAMPLES_MODE_en Mode, |
| SSRC_Params_t* pSSRC_Params ); |
| |
| |
| /****************************************************************************************/ |
| /* */ |
| /* FUNCTION: SSRC_GetScratchSize */ |
| /* */ |
| /* DESCRIPTION: */ |
| /* This function retrieves the scratch size for a given conversion ratio and */ |
| /* for given buffer sizes at the input and at the output */ |
| /* */ |
| /* PARAMETERS: */ |
| /* pSSRC_Params pointer to the instance parameters */ |
| /* pScratchSize pointer to the scratch size. The SSRC_GetScratchSize */ |
| /* function will fill in the correct value (in bytes). */ |
| /* */ |
| /* RETURNS: */ |
| /* SSRC_OK when the function call succeeds */ |
| /* SSRC_INVALID_FS When the requested input or output sampling rates */ |
| /* are invalid. */ |
| /* SSRC_INVALID_NR_CHANNELS When the channel format is not equal to LVM_MONO */ |
| /* or LVM_STEREO */ |
| /* SSRC_NULL_POINTER When any of the input pointers is a NULL pointer */ |
| /* SSRC_WRONG_NR_SAMPLES When the number of samples on the input or on the output */ |
| /* are incorrect */ |
| /* */ |
| /* NOTES: */ |
| /* */ |
| /****************************************************************************************/ |
| |
| SSRC_ReturnStatus_en SSRC_GetScratchSize( SSRC_Params_t* pSSRC_Params, |
| LVM_INT32* pScratchSize ); |
| |
| |
| /****************************************************************************************/ |
| /* */ |
| /* FUNCTION: SSRC_Init */ |
| /* */ |
| /* DESCRIPTION: */ |
| /* This function is used to initialize the SSRC module instance. */ |
| /* */ |
| /* PARAMETERS: */ |
| /* pSSRC_Instance Instance pointer */ |
| /* */ |
| /* pSSRC_Scratch pointer to the scratch memory */ |
| /* pSSRC_Params pointer to the instance parameters */ |
| /* pInputInScratch, pointer to a location in the scratch memory that can be */ |
| /* used to store the input samples (e.g. to save memory) */ |
| /* pOutputInScratch pointer to a location in the scratch memory that can be */ |
| /* used to store the output samples (e.g. to save memory) */ |
| /* */ |
| /* RETURNS: */ |
| /* SSRC_OK Succeeded */ |
| /* SSRC_INVALID_FS When the requested input or output sampling rates */ |
| /* are invalid. */ |
| /* SSRC_INVALID_NR_CHANNELS When the channel format is not equal to LVM_MONO */ |
| /* or LVM_STEREO */ |
| /* SSRC_WRONG_NR_SAMPLES When the number of samples on the input or the output */ |
| /* are incorrect */ |
| /* SSRC_NULL_POINTER When any of the input pointers is a NULL pointer */ |
| /* SSRC_ALLINGMENT_ERROR When the instance memory or the scratch memory is not */ |
| /* 4 bytes alligned */ |
| /* */ |
| /* NOTES: */ |
| /* 1. The init function will clear the internal state */ |
| /* */ |
| /****************************************************************************************/ |
| |
| SSRC_ReturnStatus_en SSRC_Init( SSRC_Instance_t* pSSRC_Instance, |
| SSRC_Scratch_t* pSSRC_Scratch, |
| SSRC_Params_t* pSSRC_Params, |
| LVM_INT16** ppInputInScratch, |
| LVM_INT16** ppOutputInScratch); |
| |
| |
| /****************************************************************************************/ |
| /* */ |
| /* FUNCTION: SSRC_SetGains */ |
| /* */ |
| /* DESCRIPTION: */ |
| /* This function sets headroom gain and the post gain of the SSRC */ |
| /* */ |
| /* PARAMETERS: */ |
| /* bHeadroomGainEnabled parameter to enable or disable the headroom gain of the */ |
| /* SSRC. The default value is LVM_MODE_ON. LVM_MODE_OFF */ |
| /* can be used in case it can be guaranteed that the input */ |
| /* level is below -6dB in all cases (the default headroom */ |
| /* is -6 dB) */ |
| /* */ |
| /* bOutputGainEnabled parameter to enable or disable the output gain. The */ |
| /* default value is LVM_MODE_ON */ |
| /* */ |
| /* OutputGain the value of the output gain. The output gain is a linear */ |
| /* gain value. 0x7FFF is equal to +6 dB and 0x0000 corresponds */ |
| /* to -inf dB. By default, a 3dB gain is applied, resulting */ |
| /* in an overall gain of -3dB (-6dB headroom + 3dB output gain)*/ |
| /* */ |
| /* RETURNS: */ |
| /* SSRC_OK Succeeded */ |
| /* SSRC_NULL_POINTER When pSSRC_Instance is a NULL pointer */ |
| /* SSRC_INVALID_MODE Wrong value used for the bHeadroomGainEnabled or the */ |
| /* bOutputGainEnabled parameters. */ |
| /* SSRC_INVALID_VALUE When OutputGain is out to the range [0;32767] */ |
| /* */ |
| /* NOTES: */ |
| /* 1. The SSRC_SetGains function is an optional function that should only be used */ |
| /* in rare cases. Preferably, use the default settings. */ |
| /* */ |
| /****************************************************************************************/ |
| |
| SSRC_ReturnStatus_en SSRC_SetGains( SSRC_Instance_t* pSSRC_Instance, |
| LVM_Mode_en bHeadroomGainEnabled, |
| LVM_Mode_en bOutputGainEnabled, |
| LVM_INT16 OutputGain ); |
| |
| |
| /****************************************************************************************/ |
| /* */ |
| /* FUNCTION: SSRC_Process */ |
| /* */ |
| /* DESCRIPTION: */ |
| /* Process function for the SSRC module. */ |
| /* */ |
| /* PARAMETERS: */ |
| /* pSSRC_Instance Instance pointer */ |
| /* pSSRC_AudioIn Pointer to the input data */ |
| /* pSSRC_AudioOut Pointer to the output data */ |
| /* */ |
| /* RETURNS: */ |
| /* SSRC_OK Succeeded */ |
| /* SSRC_NULL_POINTER When one of pSSRC_Instance, pSSRC_AudioIn or pSSRC_AudioOut */ |
| /* is NULL */ |
| /* */ |
| /* NOTES: */ |
| /* */ |
| /****************************************************************************************/ |
| |
| SSRC_ReturnStatus_en SSRC_Process( SSRC_Instance_t* pSSRC_Instance, |
| LVM_INT16* pSSRC_AudioIn, |
| LVM_INT16* pSSRC_AudioOut); |
| |
| /****************************************************************************************/ |
| |
| #endif /* __SSRC_H__ */ |
