1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 /* 39 * Audio Duplex: forward audio from BTstack audio source to audio sink - test for audio interface 40 * 41 */ 42 43 #include "btstack.h" 44 45 // samplerate 46 const uint32_t samplerate = 16000; 47 48 // ring buffer for audio 49 #define BUFFER_SAMPLES 1024 50 static uint16_t audio_buffer_storage[BUFFER_SAMPLES]; 51 static btstack_ring_buffer_t audio_buffer; 52 53 // mono buffer 54 #define MONO_BUFFER_LEN 128 55 static int16_t mono_buffer[MONO_BUFFER_LEN]; 56 57 // playback starts after audio_buffer is half full 58 static int playback_started; 59 60 // sample couners 61 static int count_recording; 62 static int count_playback; 63 64 static void audio_recording(const int16_t * pcm_buffer, uint16_t num_samples_to_write){ 65 count_recording += num_samples_to_write; 66 int err = btstack_ring_buffer_write(&audio_buffer, (uint8_t *) pcm_buffer, num_samples_to_write * 2); 67 if (err){ 68 printf("Failed to store %u samples\n", num_samples_to_write); 69 } 70 } 71 72 static void audio_playback(int16_t * pcm_buffer, uint16_t num_samples_to_write){ 73 int num_samples_in_buffer = btstack_ring_buffer_bytes_available(&audio_buffer) / 2; 74 if (playback_started == 0){ 75 if ( num_samples_in_buffer < (BUFFER_SAMPLES / 2)) return; 76 playback_started = 1; 77 } 78 count_playback += num_samples_to_write; 79 while (num_samples_to_write){ 80 num_samples_in_buffer = btstack_ring_buffer_bytes_available(&audio_buffer) / 2; 81 int num_samples_ready = btstack_min(num_samples_in_buffer, num_samples_to_write); 82 // limit by mono_buffer 83 int num_samples_from_buffer = btstack_min(num_samples_ready, MONO_BUFFER_LEN); 84 if (!num_samples_from_buffer) break; 85 uint32_t bytes_read; 86 btstack_ring_buffer_read(&audio_buffer, (uint8_t *) mono_buffer, num_samples_from_buffer * 2, &bytes_read); 87 // duplicate samples for stereo output 88 int i; 89 for (i=0; i < num_samples_from_buffer;i++){ 90 *pcm_buffer++ = mono_buffer[i]; 91 *pcm_buffer++ = mono_buffer[i]; 92 num_samples_to_write--; 93 } 94 } 95 96 // warn about underrun 97 if (num_samples_to_write){ 98 printf("Buffer underrun - recording %u, playback %u - delta %d!\n", count_recording, count_playback, count_recording - count_playback); 99 } 100 101 // fill rest with silence 102 while (num_samples_to_write){ 103 *pcm_buffer++ = 0; 104 *pcm_buffer++ = 0; 105 num_samples_to_write--; 106 } 107 } 108 109 int btstack_main(int argc, const char * argv[]); 110 int btstack_main(int argc, const char * argv[]){ 111 (void)argc; 112 (void)argv; 113 114 // check audio interface 115 const btstack_audio_sink_t * audio_sink = btstack_audio_sink_get_instance(); 116 if (!audio_sink){ 117 printf("BTstack Audio Sink not setup\n"); 118 return 10; 119 } 120 121 const btstack_audio_source_t * audio_source = btstack_audio_source_get_instance(); 122 if (!audio_source){ 123 printf("BTstack Audio Source not setup\n"); 124 return 10; 125 } 126 127 // prepare audio buffer 128 btstack_ring_buffer_init(&audio_buffer, (uint8_t*) &audio_buffer_storage[0], sizeof(audio_buffer_storage)); 129 130 // setup audio: mono input -> stereo output 131 audio_source->init(1, samplerate, &audio_recording); 132 audio_sink->init(2, samplerate, &audio_playback); 133 134 // start duplex 135 audio_source->start_stream(); 136 audio_sink->start_stream(); 137 138 return 0; 139 } 140