xref: /btstack/example/le_audio_demo_util_sink.c (revision 79d6b6059c1f873666dfb7676264712a93b8dbf1)
1 /*
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37 
38 #define BTSTACK_FILE__ "le_audio_demo_util_sink.c"
39 
40 #include "le_audio_demo_util_sink.h"
41 
42 #include "btstack_bool.h"
43 #include "btstack_config.h"
44 #include <btstack_debug.h>
45 #include <printf.h>
46 
47 #include "hci.h"
48 #include "btstack_audio.h"
49 #include "btstack_lc3_google.h"
50 #include "btstack_lc3plus_fraunhofer.h"
51 
52 #include "hxcmod.h"
53 #include "mods/mod.h"
54 
55 #ifdef HAVE_POSIX_FILE_IO
56 #include "wav_util.h"
57 #include "btstack_ring_buffer.h"
58 
59 #endif
60 
61 //#define DEBUG_PLC
62 #ifdef DEBUG_PLC
63 #define printf_plc(...) printf(__VA_ARGS__)
64 #else
65 #define printf_plc(...)  (void)(0);
66 #endif
67 
68 #define MAX_CHANNELS 2
69 #define MAX_SAMPLES_PER_FRAME 480
70 #define MAX_LC3_FRAME_BYTES   155
71 
72 // playback
73 #define MAX_NUM_LC3_FRAMES   15
74 #define MAX_BYTES_PER_SAMPLE 4
75 #define PLAYBACK_BUFFER_SIZE (MAX_NUM_LC3_FRAMES * MAX_SAMPLES_PER_FRAME * MAX_BYTES_PER_SAMPLE)
76 #define PLAYBACK_START_MS (MAX_NUM_LC3_FRAMES * 20 / 3)
77 
78 #define ANSI_COLOR_RED     "\x1b[31m"
79 #define ANSI_COLOR_GREEN   "\x1b[32m"
80 #define ANSI_COLOR_YELLOW  "\x1b[33m"
81 #define ANSI_COLOR_BLUE    "\x1b[34m"
82 #define ANSI_COLOR_MAGENTA "\x1b[35m"
83 #define ANSI_COLOR_CYAN    "\x1b[36m"
84 #define ANSI_COLOR_RESET   "\x1b[0m"
85 
86 // SINK
87 
88 static const char * le_audio_demo_sink_filename_wav;
89 
90 static btstack_lc3_frame_duration_t le_audio_demo_sink_frame_duration;
91 static hci_iso_type_t               le_audio_demo_sink_type;
92 
93 static uint32_t le_audio_demo_sink_sampling_frequency_hz;
94 static uint16_t le_audio_demo_sink_num_samples_per_frame;
95 static uint8_t  le_audio_demo_sink_num_streams;
96 static uint8_t  le_audio_demo_sink_num_channels_per_stream;
97 static uint8_t  le_audio_demo_sink_num_channels;
98 static uint16_t le_audio_demo_sink_octets_per_frame;
99 static uint16_t le_audio_demo_sink_iso_interval_1250us;
100 static uint8_t  le_audio_demo_sink_flush_timeout;
101 static uint8_t  le_audio_demo_sink_pre_transmission_offset;
102 
103 // playback
104 static uint16_t              playback_start_threshold_bytes;
105 static bool                  playback_active;
106 static uint8_t               playback_buffer_storage[PLAYBACK_BUFFER_SIZE];
107 static btstack_ring_buffer_t playback_buffer;
108 
109 // PLC
110 static bool     stream_last_packet_received[MAX_CHANNELS];
111 static uint16_t stream_last_packet_sequence[MAX_CHANNELS];
112 static uint16_t group_last_packet_sequence;
113 static bool     group_last_packet_received;
114 static uint16_t plc_timeout_initial_ms;
115 static uint16_t plc_timeout_subsequent_ms;
116 
117 static uint32_t le_audio_demo_sink_lc3_frames;
118 static uint32_t samples_received;
119 static uint32_t samples_played;
120 static uint32_t samples_dropped;
121 
122 static btstack_timer_source_t next_packet_timer;
123 
124 // lc3 decoder
125 static bool le_audio_demo_lc3plus_decoder_requested = false;
126 static const btstack_lc3_decoder_t * lc3_decoder;
127 static int16_t pcm[MAX_CHANNELS * MAX_SAMPLES_PER_FRAME];
128 static bool have_pcm[MAX_CHANNELS];
129 
130 static btstack_lc3_decoder_google_t google_decoder_contexts[MAX_CHANNELS];
131 #ifdef HAVE_LC3PLUS
132 static btstack_lc3plus_fraunhofer_decoder_t fraunhofer_decoder_contexts[MAX_CHANNELS];
133 #endif
134 static void * decoder_contexts[MAX_CHANNELS];
135 
136 static void le_audio_connection_sink_playback(int16_t * buffer, uint16_t num_samples){
137     // called from lower-layer but guaranteed to be on main thread
138     log_info("Playback: need %u, have %u", num_samples, btstack_ring_buffer_bytes_available(&playback_buffer) / (le_audio_demo_sink_num_channels * 2));
139 
140     samples_played += num_samples;
141 
142     uint32_t bytes_needed = num_samples * le_audio_demo_sink_num_channels * 2;
143     if (playback_active == false){
144         if (btstack_ring_buffer_bytes_available(&playback_buffer) >= playback_start_threshold_bytes) {
145             log_info("Playback started");
146             playback_active = true;
147         }
148     } else {
149         if (bytes_needed > btstack_ring_buffer_bytes_available(&playback_buffer)) {
150             log_info("Playback underrun");
151             printf("Playback Underrun\n");
152             // empty buffer
153             uint32_t bytes_read;
154             btstack_ring_buffer_read(&playback_buffer, (uint8_t *) buffer, bytes_needed, &bytes_read);
155             playback_active = false;
156         }
157     }
158 
159     if (playback_active){
160         uint32_t bytes_read;
161         btstack_ring_buffer_read(&playback_buffer, (uint8_t *) buffer, bytes_needed, &bytes_read);
162         btstack_assert(bytes_read == bytes_needed);
163     } else {
164         memset(buffer, 0, bytes_needed);
165     }
166 }
167 
168 static void setup_lc3_decoder(void){
169     uint8_t channel;
170     for (channel = 0 ; channel < le_audio_demo_sink_num_channels ; channel++){
171         // pick decoder
172         void * decoder_context = NULL;
173 #ifdef HAVE_LC3PLUS
174         if (use_lc3plus_decoder){
175             decoder_context = &fraunhofer_decoder_contexts[channel];
176             lc3_decoder = btstack_lc3plus_fraunhofer_decoder_init_instance(decoder_context);
177         }
178         else
179 #endif
180         {
181             decoder_context = &google_decoder_contexts[channel];
182             lc3_decoder = btstack_lc3_decoder_google_init_instance(decoder_context);
183         }
184         decoder_contexts[channel] = decoder_context;
185         lc3_decoder->configure(decoder_context, le_audio_demo_sink_sampling_frequency_hz, le_audio_demo_sink_frame_duration, le_audio_demo_sink_octets_per_frame);
186     }
187     btstack_assert(le_audio_demo_sink_num_samples_per_frame <= MAX_SAMPLES_PER_FRAME);
188 }
189 
190 static void store_samples_in_ringbuffer(void){
191     // check if we have all channels
192     uint8_t channel;
193     for (channel = 0; channel < le_audio_demo_sink_num_channels; channel++){
194         if (have_pcm[channel] == false) return;
195     }
196 #ifdef HAVE_POSIX_FILE_IO
197     // write wav samples
198     wav_writer_write_int16(le_audio_demo_sink_num_channels * le_audio_demo_sink_num_samples_per_frame, pcm);
199 #endif
200     // store samples in playback buffer
201     uint32_t bytes_to_store = le_audio_demo_sink_num_channels * le_audio_demo_sink_num_samples_per_frame * 2;
202     samples_received += le_audio_demo_sink_num_samples_per_frame;
203     if (btstack_ring_buffer_bytes_free(&playback_buffer) >= bytes_to_store) {
204         btstack_ring_buffer_write(&playback_buffer, (uint8_t *) pcm, bytes_to_store);
205     } else {
206         printf("Samples dropped\n");
207         samples_dropped += le_audio_demo_sink_num_samples_per_frame;
208     }
209     memset(have_pcm, 0, sizeof(have_pcm));
210 }
211 
212 static void plc_do(uint8_t stream_index) {
213     // inject packet
214     uint8_t tmp_BEC_detect;
215     uint8_t BFI = 1;
216     uint8_t i;
217     for (i = 0; i < le_audio_demo_sink_num_channels_per_stream; i++){
218         uint8_t effective_channel = stream_index + i;
219         (void) lc3_decoder->decode_signed_16(decoder_contexts[effective_channel], NULL, BFI,
220                                              &pcm[effective_channel], le_audio_demo_sink_num_channels,
221                                              &tmp_BEC_detect);
222     }
223     // and store in ringbuffer when PCM for all channels is available
224     store_samples_in_ringbuffer();
225 }
226 
227 //
228 // Perform PLC for packets missing in previous intervals
229 //
230 // assumptions:
231 // - packet sequence number is monotonic increasing
232 // - if packet with seq nr x is received, all packets with smaller seq number are either received or missed
233 static void plc_check(uint16_t packet_sequence_number) {
234     while (group_last_packet_sequence != packet_sequence_number){
235         uint8_t i;
236         for (i=0;i<le_audio_demo_sink_num_streams;i++){
237             // deal with first packet missing. inject silent samples, pcm buffer is memset to zero at start
238             if (stream_last_packet_received[i] == false){
239                 printf_plc("- ISO #%u, very first packet missing\n", i);
240                 have_pcm[i] = true;
241                 store_samples_in_ringbuffer();
242 
243                 stream_last_packet_received[i] = true;
244                 stream_last_packet_sequence[i] = group_last_packet_sequence;
245                 continue;
246             }
247 
248             // missing packet if big sequence counter is higher than bis sequence counter
249             if (btstack_time16_delta(group_last_packet_sequence, stream_last_packet_sequence[i]) > 0) {
250                 printf_plc("- ISO #%u, PLC for %u\n", i, group_last_packet_sequence);
251                 plc_do(i);
252                 btstack_assert((stream_last_packet_sequence[i] + 1) == group_last_packet_sequence);
253                 stream_last_packet_sequence[i] = group_last_packet_sequence;
254             }
255         }
256         group_last_packet_sequence++;
257     }
258 }
259 
260 static void plc_timeout(btstack_timer_source_t * timer) {
261     // Restart timer. This will loose sync with ISO interval, but if we stop caring if we loose that many packets
262     btstack_run_loop_set_timer(timer, plc_timeout_subsequent_ms);
263     btstack_run_loop_set_timer_handler(timer, plc_timeout);
264     btstack_run_loop_add_timer(timer);
265 
266     switch (le_audio_demo_sink_type){
267         case HCI_ISO_TYPE_CIS:
268             // assume no packet received in iso interval => FT packets missed
269             plc_check(group_last_packet_sequence + le_audio_demo_sink_flush_timeout);
270             break;
271         case HCI_ISO_TYPE_BIS:
272             // assume PTO not used => 1 packet missed
273             plc_check(group_last_packet_sequence + 1);
274             break;
275         default:
276             btstack_unreachable();
277             break;
278     }
279 }
280 
281 void le_audio_demo_util_sink_init(const char * filename_wav){
282     le_audio_demo_sink_filename_wav = filename_wav;
283 }
284 
285 void le_audio_demo_util_sink_enable_lc3plus(bool enable){
286     le_audio_demo_lc3plus_decoder_requested = enable;
287 }
288 
289 void le_audio_demo_util_sink_configure_general(uint8_t num_streams, uint8_t num_channels_per_stream,
290                                                uint32_t sampling_frequency_hz,
291                                                btstack_lc3_frame_duration_t frame_duration, uint16_t octets_per_frame,
292                                                uint32_t iso_interval_1250us) {
293     le_audio_demo_sink_sampling_frequency_hz = sampling_frequency_hz;
294     le_audio_demo_sink_frame_duration = frame_duration;
295     le_audio_demo_sink_octets_per_frame = octets_per_frame;
296     le_audio_demo_sink_iso_interval_1250us = iso_interval_1250us;
297     le_audio_demo_sink_num_streams = num_streams;
298     le_audio_demo_sink_num_channels_per_stream = num_channels_per_stream;
299 
300     le_audio_demo_sink_num_channels = le_audio_demo_sink_num_streams * le_audio_demo_sink_num_channels_per_stream;
301     btstack_assert((le_audio_demo_sink_num_channels == 1) || (le_audio_demo_sink_num_channels == 2));
302 
303     le_audio_demo_sink_lc3_frames = 0;
304 
305     le_audio_demo_sink_num_samples_per_frame = btstack_lc3_samples_per_frame(le_audio_demo_sink_sampling_frequency_hz, le_audio_demo_sink_frame_duration);
306 
307     // switch to lc3plus if requested and possible
308     bool use_lc3plus_decoder = le_audio_demo_lc3plus_decoder_requested && (frame_duration == BTSTACK_LC3_FRAME_DURATION_10000US);
309 
310     // init decoder
311     setup_lc3_decoder();
312 
313     printf("Configure: %u streams, %u channels per stream, sampling rate %u, samples per frame %u, lc3plus %u\n",
314            num_streams, num_channels_per_stream, sampling_frequency_hz, le_audio_demo_sink_num_samples_per_frame, use_lc3plus_decoder);
315 
316 #ifdef HAVE_POSIX_FILE_IO
317     // create wav file
318     printf("WAV file: %s\n", le_audio_demo_sink_filename_wav);
319     wav_writer_open(le_audio_demo_sink_filename_wav, le_audio_demo_sink_num_channels, le_audio_demo_sink_sampling_frequency_hz);
320 #endif
321 
322     // init playback buffer
323     btstack_ring_buffer_init(&playback_buffer, playback_buffer_storage, PLAYBACK_BUFFER_SIZE);
324 
325     // calc start threshold in bytes for PLAYBACK_START_MS
326     playback_start_threshold_bytes = (sampling_frequency_hz / 1000 * PLAYBACK_START_MS) * le_audio_demo_sink_num_channels * 2;
327 
328     // start playback
329     const btstack_audio_sink_t * sink = btstack_audio_sink_get_instance();
330     if (sink != NULL){
331         sink->init(le_audio_demo_sink_num_channels, le_audio_demo_sink_sampling_frequency_hz, le_audio_connection_sink_playback);
332         sink->start_stream();
333     }
334 }
335 
336 void le_audio_demo_util_sink_configure_unicast(uint8_t num_streams, uint8_t num_channels_per_stream, uint32_t sampling_frequency_hz,
337                                                btstack_lc3_frame_duration_t frame_duration, uint16_t octets_per_frame,
338                                                uint32_t iso_interval_1250us, uint8_t flush_timeout){
339     le_audio_demo_sink_type = HCI_ISO_TYPE_CIS;
340     le_audio_demo_sink_flush_timeout = flush_timeout;
341 
342     // set playback start: FT * ISO Interval + 10 ms
343     uint16_t playback_start_ms = flush_timeout * (iso_interval_1250us * 5 / 4) + 10;
344     uint16_t playback_start_samples = sampling_frequency_hz / 1000 * playback_start_ms;
345     playback_start_threshold_bytes = playback_start_samples * num_streams * num_channels_per_stream * 2;
346     printf("Playback: start %u ms (%u samples, %u bytes)\n", playback_start_ms, playback_start_samples, playback_start_threshold_bytes);
347 
348     // set subsequent plc timeout: FT * ISO Interval
349     plc_timeout_subsequent_ms = flush_timeout * iso_interval_1250us * 5 / 4;
350 
351     // set initial plc timeout:FT * ISO Interval + 4 ms
352     plc_timeout_initial_ms = plc_timeout_subsequent_ms + 4;
353 
354     printf("PLC: initial timeout    %u ms\n", plc_timeout_initial_ms);
355     printf("PLC: subsequent timeout %u ms\n", plc_timeout_subsequent_ms);
356 
357     le_audio_demo_util_sink_configure_general(num_streams, num_channels_per_stream, sampling_frequency_hz,
358                                               frame_duration, octets_per_frame, iso_interval_1250us);
359 }
360 
361 void le_audio_demo_util_sink_configure_broadcast(uint8_t num_streams, uint8_t num_channels_per_stream, uint32_t sampling_frequency_hz,
362                                                btstack_lc3_frame_duration_t frame_duration, uint16_t octets_per_frame,
363                                                uint32_t iso_interval_1250us, uint8_t pre_transmission_offset) {
364     le_audio_demo_sink_type = HCI_ISO_TYPE_BIS;
365     le_audio_demo_sink_pre_transmission_offset = pre_transmission_offset;
366 
367     // set playback start: ISO Interval + 10 ms
368     uint16_t playback_start_ms = (iso_interval_1250us * 5 / 4) + 10;
369     uint16_t playback_start_samples = sampling_frequency_hz / 1000 * playback_start_ms;
370     playback_start_threshold_bytes = playback_start_samples * num_streams * num_channels_per_stream * 2;
371     printf("Playback: start %u ms (%u samples, %u bytes)\n", playback_start_ms, playback_start_samples, playback_start_threshold_bytes);
372 
373     // set subsequent plc timeout: ISO Interval
374     plc_timeout_subsequent_ms = iso_interval_1250us * 5 / 4;
375 
376     // set initial plc timeout: ISO Interval + 4 ms
377     plc_timeout_initial_ms = plc_timeout_subsequent_ms + 4;
378 
379     printf("PLC: initial timeout    %u ms\n", plc_timeout_initial_ms);
380     printf("PLC: subsequent timeout %u ms\n", plc_timeout_subsequent_ms);
381 
382     le_audio_demo_util_sink_configure_unicast(num_streams, num_channels_per_stream, sampling_frequency_hz, frame_duration,
383                                               octets_per_frame, iso_interval_1250us, pre_transmission_offset);
384 }
385 
386 void le_audio_demo_util_sink_receive(uint8_t stream_index, uint8_t *packet, uint16_t size) {
387     uint16_t header = little_endian_read_16(packet, 0);
388     hci_con_handle_t con_handle = header & 0x0fff;
389     uint8_t pb_flag = (header >> 12) & 3;
390     uint8_t ts_flag = (header >> 14) & 1;
391     uint16_t iso_load_len = little_endian_read_16(packet, 2);
392 
393     uint16_t offset = 4;
394     uint32_t time_stamp = 0;
395     if (ts_flag){
396         uint32_t time_stamp = little_endian_read_32(packet, offset);
397         offset += 4;
398     }
399 
400     uint32_t receive_time_ms = btstack_run_loop_get_time_ms();
401 
402     uint16_t packet_sequence_number = little_endian_read_16(packet, offset);
403     offset += 2;
404 
405     uint16_t header_2 = little_endian_read_16(packet, offset);
406     uint16_t iso_sdu_length = header_2 & 0x3fff;
407     uint8_t packet_status_flag = (uint8_t) (header_2 >> 14);
408     offset += 2;
409 
410     if (iso_sdu_length == 0) return;
411 
412     if (iso_sdu_length != le_audio_demo_sink_num_channels_per_stream * le_audio_demo_sink_octets_per_frame) {
413         printf("ISO Length %u != %u * %u\n", iso_sdu_length, le_audio_demo_sink_num_channels_per_stream, le_audio_demo_sink_octets_per_frame);
414         return;
415     }
416 
417     // start with first packet on first stream
418     if (group_last_packet_received == false){
419         if (stream_index != 0){
420             printf("Ignore first packet for second stream\n");
421             return;
422         }
423         group_last_packet_received = true;
424         group_last_packet_sequence = packet_sequence_number;
425     }
426 
427     if (stream_last_packet_received[stream_index]) {
428         printf_plc("ISO #%u, receive %u\n", stream_index, packet_sequence_number);
429 
430         int16_t packet_sequence_delta = btstack_time16_delta(packet_sequence_number,
431                                                              stream_last_packet_sequence[stream_index]);
432         if (packet_sequence_delta < 1) {
433             // drop delayed packet that had already been generated by PLC
434             printf_plc("- dropping delayed packet. Current sequence number %u, last received or generated by PLC: %u\n",
435                        packet_sequence_number, stream_last_packet_sequence[stream_index]);
436             return;
437         }
438         // simple check
439         if (packet_sequence_number != stream_last_packet_sequence[stream_index] + 1) {
440             printf_plc("- ISO #%u, missing %u\n", stream_index, stream_last_packet_sequence[stream_index] + 1);
441         }
442     } else {
443         printf_plc("ISO %u, first packet seq number %u\n", stream_index, packet_sequence_number);
444         stream_last_packet_received[stream_index] = true;
445     }
446 
447     plc_check(packet_sequence_number);
448 
449     uint8_t i;
450     for (i = 0 ; i < le_audio_demo_sink_num_channels_per_stream ; i++){
451         // decode codec frame
452         uint8_t tmp_BEC_detect;
453         uint8_t BFI = 0;
454         uint8_t effective_channel = stream_index + i;
455         (void) lc3_decoder->decode_signed_16(decoder_contexts[effective_channel], &packet[offset], BFI,
456                                              &pcm[effective_channel], le_audio_demo_sink_num_channels,
457                                              &tmp_BEC_detect);
458         offset += le_audio_demo_sink_octets_per_frame;
459         have_pcm[stream_index + i] = true;
460     }
461 
462     store_samples_in_ringbuffer();
463 
464     log_info("Samples in playback buffer %5u", btstack_ring_buffer_bytes_available(&playback_buffer) / (le_audio_demo_sink_num_channels * 2));
465 
466     le_audio_demo_sink_lc3_frames++;
467 
468     // PLC
469     btstack_run_loop_remove_timer(&next_packet_timer);
470     btstack_run_loop_set_timer(&next_packet_timer, plc_timeout_initial_ms);
471     btstack_run_loop_set_timer_handler(&next_packet_timer, plc_timeout);
472     btstack_run_loop_add_timer(&next_packet_timer);
473 
474     if (samples_received >= le_audio_demo_sink_sampling_frequency_hz){
475         printf("LC3 Frames: %4u - samples received %5u, played %5u, dropped %5u\n", le_audio_demo_sink_lc3_frames, samples_received, samples_played, samples_dropped);
476         samples_received = 0;
477         samples_dropped  =  0;
478         samples_played = 0;
479     }
480 
481     stream_last_packet_sequence[stream_index] = packet_sequence_number;
482 }
483 
484 /**
485  * @brief Close sink: close wav file, stop playback
486  */
487 void le_audio_demo_util_sink_close(void){
488 #ifdef HAVE_POSIX_FILE_IO
489     printf("Close WAV file\n");
490     wav_writer_close();
491 #endif
492     // stop playback
493     const btstack_audio_sink_t * sink = btstack_audio_sink_get_instance();
494     if (sink != NULL){
495         sink->stop_stream();
496     }
497     // stop timer
498     btstack_run_loop_remove_timer(&next_packet_timer);
499 }