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 46 // uncomment to test start/stop of loopback / audio driver 47 // #define TEST_START_STOP_INTERVAL 5000 48 49 #ifdef TEST_START_STOP_INTERVAL 50 static void stop_loopback(btstack_timer_source_t * ts); 51 #endif 52 53 static btstack_timer_source_t start_stop_timer; 54 55 // samplerate 56 const uint32_t samplerate = 16000; 57 58 // ring buffer for audio 59 #define BUFFER_SAMPLES 1024 60 static uint16_t audio_buffer_storage[BUFFER_SAMPLES]; 61 static btstack_ring_buffer_t audio_buffer; 62 63 // mono buffer 64 #define MONO_BUFFER_LEN 128 65 static int16_t mono_buffer[MONO_BUFFER_LEN]; 66 67 // playback starts after audio_buffer is half full 68 static int playback_started; 69 70 // sample couners 71 static int count_recording; 72 static int count_playback; 73 74 static void audio_recording(const int16_t * pcm_buffer, uint16_t num_samples_to_write){ 75 count_recording += num_samples_to_write; 76 int err = btstack_ring_buffer_write(&audio_buffer, (uint8_t *) pcm_buffer, num_samples_to_write * 2); 77 if (err){ 78 printf("Failed to store %u samples\n", num_samples_to_write); 79 } 80 } 81 82 static void audio_playback(int16_t * pcm_buffer, uint16_t num_samples_to_write){ 83 int num_samples_in_buffer = btstack_ring_buffer_bytes_available(&audio_buffer) / 2; 84 if (playback_started == 0){ 85 if ( num_samples_in_buffer < (BUFFER_SAMPLES / 2)) return; 86 playback_started = 1; 87 } 88 count_playback += num_samples_to_write; 89 while (num_samples_to_write){ 90 num_samples_in_buffer = btstack_ring_buffer_bytes_available(&audio_buffer) / 2; 91 int num_samples_ready = btstack_min(num_samples_in_buffer, num_samples_to_write); 92 // limit by mono_buffer 93 int num_samples_from_buffer = btstack_min(num_samples_ready, MONO_BUFFER_LEN); 94 if (!num_samples_from_buffer) break; 95 uint32_t bytes_read; 96 btstack_ring_buffer_read(&audio_buffer, (uint8_t *) mono_buffer, num_samples_from_buffer * 2, &bytes_read); 97 // duplicate samples for stereo output 98 int i; 99 for (i=0; i < num_samples_from_buffer;i++){ 100 *pcm_buffer++ = mono_buffer[i]; 101 *pcm_buffer++ = mono_buffer[i]; 102 num_samples_to_write--; 103 } 104 } 105 106 // warn about underrun 107 if (num_samples_to_write){ 108 printf("Buffer underrun - recording %u, playback %u - delta %d!\n", count_recording, count_playback, count_recording - count_playback); 109 } 110 111 // fill rest with silence 112 while (num_samples_to_write){ 113 *pcm_buffer++ = 0; 114 *pcm_buffer++ = 0; 115 num_samples_to_write--; 116 } 117 } 118 119 static void start_loopback(btstack_timer_source_t * ts){ 120 121 const btstack_audio_sink_t * audio_sink = btstack_audio_sink_get_instance(); 122 const btstack_audio_source_t * audio_source = btstack_audio_source_get_instance(); 123 124 // prepare audio buffer 125 btstack_ring_buffer_init(&audio_buffer, (uint8_t*) &audio_buffer_storage[0], sizeof(audio_buffer_storage)); 126 127 // setup audio: mono input -> stereo output 128 audio_sink->init(2, samplerate, &audio_playback); 129 audio_source->init(1, samplerate, &audio_recording); 130 131 // start duplex 132 audio_sink->start_stream(); 133 audio_source->start_stream(); 134 135 printf("Start Audio Loopback\n"); 136 137 #ifdef TEST_START_STOP_INTERVAL 138 // schedule stop 139 btstack_run_loop_set_timer_handler(ts, &stop_loopback); 140 btstack_run_loop_set_timer(ts, TEST_START_STOP_INTERVAL); 141 btstack_run_loop_add_timer(ts); 142 #endif 143 } 144 145 #ifdef TEST_START_STOP_INTERVAL 146 static void stop_loopback(btstack_timer_source_t * ts){ 147 const btstack_audio_sink_t * audio_sink = btstack_audio_sink_get_instance(); 148 const btstack_audio_source_t * audio_source = btstack_audio_source_get_instance(); 149 150 // stop streams 151 audio_sink->stop_stream(); 152 audio_source->stop_stream(); 153 154 // close audio 155 audio_sink->close(); 156 audio_source->close(); 157 158 playback_started = 0; 159 160 printf("Stop Audio Loopback\n"); 161 162 // schedule stop 163 btstack_run_loop_set_timer_handler(ts, &start_loopback); 164 btstack_run_loop_set_timer(ts, TEST_START_STOP_INTERVAL); 165 btstack_run_loop_add_timer(ts); 166 } 167 #endif 168 169 int btstack_main(int argc, const char * argv[]); 170 int btstack_main(int argc, const char * argv[]){ 171 (void)argc; 172 (void)argv; 173 174 // check audio interface 175 const btstack_audio_sink_t * audio_sink = btstack_audio_sink_get_instance(); 176 if (!audio_sink){ 177 printf("BTstack Audio Sink not setup\n"); 178 return 10; 179 } 180 181 const btstack_audio_source_t * audio_source = btstack_audio_source_get_instance(); 182 if (!audio_source){ 183 printf("BTstack Audio Source not setup\n"); 184 return 10; 185 } 186 187 start_loopback(&start_stop_timer); 188 189 return 0; 190 } 191