cubeb_resampler.h (3412B)
1 /* 2 * Copyright © 2014 Mozilla Foundation 3 * 4 * This program is made available under an ISC-style license. See the 5 * accompanying file LICENSE for details. 6 */ 7 #ifndef CUBEB_RESAMPLER_H 8 #define CUBEB_RESAMPLER_H 9 10 #include "cubeb/cubeb.h" 11 12 #if defined(__cplusplus) 13 extern "C" { 14 #endif 15 16 typedef struct cubeb_resampler cubeb_resampler; 17 18 typedef enum { 19 CUBEB_RESAMPLER_QUALITY_VOIP, 20 CUBEB_RESAMPLER_QUALITY_DEFAULT, 21 CUBEB_RESAMPLER_QUALITY_DESKTOP 22 } cubeb_resampler_quality; 23 24 typedef enum { 25 CUBEB_RESAMPLER_RECLOCK_NONE, 26 CUBEB_RESAMPLER_RECLOCK_INPUT 27 } cubeb_resampler_reclock; 28 29 /** 30 * Create a resampler to adapt the requested sample rate into something that 31 * is accepted by the audio backend. 32 * @param stream A cubeb_stream instance supplied to the data callback. 33 * @param input_params Used to calculate bytes per frame and buffer size for 34 * resampling of the input side of the stream. NULL if input should not be 35 * resampled. 36 * @param output_params Used to calculate bytes per frame and buffer size for 37 * resampling of the output side of the stream. NULL if output should not be 38 * resampled. 39 * @param target_rate The sampling rate after resampling for the input side of 40 * the stream, and/or the sampling rate prior to resampling of the output side 41 * of the stream. 42 * @param callback A callback to request data for resampling. 43 * @param user_ptr User data supplied to the data callback. 44 * @param quality Quality of the resampler. 45 * @retval A non-null pointer if success. 46 */ 47 cubeb_resampler * 48 cubeb_resampler_create(cubeb_stream * stream, 49 cubeb_stream_params * input_params, 50 cubeb_stream_params * output_params, 51 unsigned int target_rate, cubeb_data_callback callback, 52 void * user_ptr, cubeb_resampler_quality quality, 53 cubeb_resampler_reclock reclock); 54 55 /** 56 * Fill the buffer with frames acquired using the data callback. Resampling will 57 * happen if necessary. 58 * @param resampler A cubeb_resampler instance. 59 * @param input_buffer A buffer of input samples 60 * @param input_frame_count The size of the buffer. Returns the number of frames 61 * consumed. 62 * @param output_buffer The buffer to be filled. 63 * @param output_frames_needed Number of frames that should be produced. 64 * @retval Number of frames that are actually produced. 65 * @retval CUBEB_ERROR on error. 66 */ 67 long 68 cubeb_resampler_fill(cubeb_resampler * resampler, void * input_buffer, 69 long * input_frame_count, void * output_buffer, 70 long output_frames_needed); 71 72 /** 73 * Destroy a cubeb_resampler. 74 * @param resampler A cubeb_resampler instance. 75 */ 76 void 77 cubeb_resampler_destroy(cubeb_resampler * resampler); 78 79 /** 80 * Returns the latency, in frames, of the resampler. 81 * @param resampler A cubeb resampler instance. 82 * @retval The latency, in frames, induced by the resampler. 83 */ 84 long 85 cubeb_resampler_latency(cubeb_resampler * resampler); 86 87 /** 88 * Test-only introspection API to ensure that there is no buffering 89 * buildup when resampling. 90 */ 91 typedef struct { 92 size_t input_input_buffer_size; 93 size_t input_output_buffer_size; 94 size_t output_input_buffer_size; 95 size_t output_output_buffer_size; 96 } cubeb_resampler_stats; 97 98 cubeb_resampler_stats 99 cubeb_resampler_stats_get(cubeb_resampler * resampler); 100 101 #if defined(__cplusplus) 102 } 103 #endif 104 105 #endif /* CUBEB_RESAMPLER_H */