1 /******************************************************************************
2 *
3 * Copyright 2016 The Android Open Source Project
4 * Copyright 2009-2012 Broadcom Corporation
5 *
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at:
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 *
18 ******************************************************************************/
19
20 #define LOG_TAG "a2dp_sbc_encoder"
21
22 #include "a2dp_sbc_encoder.h"
23
24 #include <limits.h>
25 #include <stdio.h>
26 #include <string.h>
27
28 #include "a2dp_sbc.h"
29 #include "a2dp_sbc_up_sample.h"
30 #include "bt_common.h"
31 #include "embdrv/sbc/encoder/include/sbc_encoder.h"
32 #include "osi/include/log.h"
33 #include "osi/include/osi.h"
34
35 /* Buffer pool */
36 #define A2DP_SBC_BUFFER_SIZE BT_DEFAULT_BUFFER_SIZE
37
38 // A2DP SBC encoder interval in milliseconds.
39 #define A2DP_SBC_ENCODER_INTERVAL_MS 20
40
41 /* High quality quality setting @ 44.1 khz */
42 #define A2DP_SBC_DEFAULT_BITRATE 328
43
44 #define A2DP_SBC_NON_EDR_MAX_RATE 229
45
46 /*
47 * 2DH5 payload size of:
48 * 679 bytes - (4 bytes L2CAP Header + 12 bytes AVDTP Header)
49 */
50 #define MAX_2MBPS_AVDTP_MTU 663
51 #define A2DP_SBC_MAX_PCM_ITER_NUM_PER_TICK 3
52
53 #define A2DP_SBC_MAX_HQ_FRAME_SIZE_44_1 119
54 #define A2DP_SBC_MAX_HQ_FRAME_SIZE_48 115
55
56 /* Define the bitrate step when trying to match bitpool value */
57 #define A2DP_SBC_BITRATE_STEP 5
58
59 /* Readability constants */
60 #define A2DP_SBC_FRAME_HEADER_SIZE_BYTES 4 // A2DP Spec v1.3, 12.4, Table 12.12
61 #define A2DP_SBC_SCALE_FACTOR_BITS 4 // A2DP Spec v1.3, 12.4, Table 12.13
62
63 /* offset */
64 #if (BTA_AV_CO_CP_SCMS_T == TRUE)
65 /* A2DP header will contain a CP header of size 1 */
66 #define A2DP_HDR_SIZE 2
67 #define A2DP_SBC_OFFSET (AVDT_MEDIA_OFFSET + A2DP_SBC_MPL_HDR_LEN + 1)
68 #else
69 #define A2DP_HDR_SIZE 1
70 #define A2DP_SBC_OFFSET (AVDT_MEDIA_OFFSET + A2DP_SBC_MPL_HDR_LEN)
71 #endif
72
73 typedef struct {
74 uint32_t aa_frame_counter;
75 int32_t aa_feed_counter;
76 int32_t aa_feed_residue;
77 uint32_t counter;
78 uint32_t bytes_per_tick; /* pcm bytes read each media task tick */
79 uint64_t last_frame_us;
80 } tA2DP_SBC_FEEDING_STATE;
81
82 typedef struct {
83 uint64_t session_start_us;
84
85 size_t media_read_total_expected_packets;
86 size_t media_read_total_expected_reads_count;
87 size_t media_read_total_expected_read_bytes;
88
89 size_t media_read_total_dropped_packets;
90 size_t media_read_total_actual_reads_count;
91 size_t media_read_total_actual_read_bytes;
92
93 size_t media_read_total_expected_frames;
94 size_t media_read_total_dropped_frames;
95 } a2dp_sbc_encoder_stats_t;
96
97 typedef struct {
98 a2dp_source_read_callback_t read_callback;
99 a2dp_source_enqueue_callback_t enqueue_callback;
100 uint16_t TxAaMtuSize;
101 uint8_t tx_sbc_frames;
102 bool is_peer_edr; /* True if the peer device supports EDR */
103 bool peer_supports_3mbps; /* True if the peer device supports 3Mbps EDR */
104 uint16_t peer_mtu; /* MTU of the A2DP peer */
105 uint32_t timestamp; /* Timestamp for the A2DP frames */
106 SBC_ENC_PARAMS sbc_encoder_params;
107 tA2DP_FEEDING_PARAMS feeding_params;
108 tA2DP_SBC_FEEDING_STATE feeding_state;
109 int16_t pcmBuffer[SBC_MAX_PCM_BUFFER_SIZE];
110
111 a2dp_sbc_encoder_stats_t stats;
112 } tA2DP_SBC_ENCODER_CB;
113
114 static tA2DP_SBC_ENCODER_CB a2dp_sbc_encoder_cb;
115
116 static void a2dp_sbc_encoder_update(uint16_t peer_mtu,
117 A2dpCodecConfig* a2dp_codec_config,
118 bool* p_restart_input,
119 bool* p_restart_output,
120 bool* p_config_updated);
121 static bool a2dp_sbc_read_feeding(uint32_t* bytes);
122 static void a2dp_sbc_encode_frames(uint8_t nb_frame);
123 static void a2dp_sbc_get_num_frame_iteration(uint8_t* num_of_iterations,
124 uint8_t* num_of_frames,
125 uint64_t timestamp_us);
126 static uint8_t calculate_max_frames_per_packet(void);
127 static uint16_t a2dp_sbc_source_rate();
128 static uint32_t a2dp_sbc_frame_length(void);
129
A2DP_LoadEncoderSbc(void)130 bool A2DP_LoadEncoderSbc(void) {
131 // Nothing to do - the library is statically linked
132 return true;
133 }
134
A2DP_UnloadEncoderSbc(void)135 void A2DP_UnloadEncoderSbc(void) {
136 // Nothing to do - the library is statically linked
137 }
138
a2dp_sbc_encoder_init(const tA2DP_ENCODER_INIT_PEER_PARAMS * p_peer_params,A2dpCodecConfig * a2dp_codec_config,a2dp_source_read_callback_t read_callback,a2dp_source_enqueue_callback_t enqueue_callback)139 void a2dp_sbc_encoder_init(const tA2DP_ENCODER_INIT_PEER_PARAMS* p_peer_params,
140 A2dpCodecConfig* a2dp_codec_config,
141 a2dp_source_read_callback_t read_callback,
142 a2dp_source_enqueue_callback_t enqueue_callback) {
143 memset(&a2dp_sbc_encoder_cb, 0, sizeof(a2dp_sbc_encoder_cb));
144
145 a2dp_sbc_encoder_cb.stats.session_start_us = time_get_os_boottime_us();
146
147 a2dp_sbc_encoder_cb.read_callback = read_callback;
148 a2dp_sbc_encoder_cb.enqueue_callback = enqueue_callback;
149 a2dp_sbc_encoder_cb.is_peer_edr = p_peer_params->is_peer_edr;
150 a2dp_sbc_encoder_cb.peer_supports_3mbps = p_peer_params->peer_supports_3mbps;
151 a2dp_sbc_encoder_cb.peer_mtu = p_peer_params->peer_mtu;
152 a2dp_sbc_encoder_cb.timestamp = 0;
153
154 // NOTE: Ignore the restart_input / restart_output flags - this initization
155 // happens when the connection is (re)started.
156 bool restart_input = false;
157 bool restart_output = false;
158 bool config_updated = false;
159 a2dp_sbc_encoder_update(a2dp_sbc_encoder_cb.peer_mtu, a2dp_codec_config,
160 &restart_input, &restart_output, &config_updated);
161 }
162
updateEncoderUserConfig(const tA2DP_ENCODER_INIT_PEER_PARAMS * p_peer_params,bool * p_restart_input,bool * p_restart_output,bool * p_config_updated)163 bool A2dpCodecConfigSbcSource::updateEncoderUserConfig(
164 const tA2DP_ENCODER_INIT_PEER_PARAMS* p_peer_params, bool* p_restart_input,
165 bool* p_restart_output, bool* p_config_updated) {
166 a2dp_sbc_encoder_cb.is_peer_edr = p_peer_params->is_peer_edr;
167 a2dp_sbc_encoder_cb.peer_supports_3mbps = p_peer_params->peer_supports_3mbps;
168 a2dp_sbc_encoder_cb.peer_mtu = p_peer_params->peer_mtu;
169 a2dp_sbc_encoder_cb.timestamp = 0;
170
171 if (a2dp_sbc_encoder_cb.peer_mtu == 0) {
172 LOG_ERROR(LOG_TAG,
173 "%s: Cannot update the codec encoder for %s: "
174 "invalid peer MTU",
175 __func__, name().c_str());
176 return false;
177 }
178
179 a2dp_sbc_encoder_update(a2dp_sbc_encoder_cb.peer_mtu, this, p_restart_input,
180 p_restart_output, p_config_updated);
181 return true;
182 }
183
184 // Update the A2DP SBC encoder.
185 // |peer_mtu| is the peer MTU.
186 // |a2dp_codec_config| is the A2DP codec to use for the update.
a2dp_sbc_encoder_update(uint16_t peer_mtu,A2dpCodecConfig * a2dp_codec_config,bool * p_restart_input,bool * p_restart_output,bool * p_config_updated)187 static void a2dp_sbc_encoder_update(uint16_t peer_mtu,
188 A2dpCodecConfig* a2dp_codec_config,
189 bool* p_restart_input,
190 bool* p_restart_output,
191 bool* p_config_updated) {
192 SBC_ENC_PARAMS* p_encoder_params = &a2dp_sbc_encoder_cb.sbc_encoder_params;
193 uint8_t codec_info[AVDT_CODEC_SIZE];
194 uint16_t s16SamplingFreq;
195 int16_t s16BitPool = 0;
196 int16_t s16BitRate;
197 int16_t s16FrameLen;
198 uint8_t protect = 0;
199 int min_bitpool;
200 int max_bitpool;
201
202 *p_restart_input = false;
203 *p_restart_output = false;
204 *p_config_updated = false;
205 if (!a2dp_codec_config->copyOutOtaCodecConfig(codec_info)) {
206 LOG_ERROR(LOG_TAG,
207 "%s: Cannot update the codec encoder for %s: "
208 "invalid codec config",
209 __func__, a2dp_codec_config->name().c_str());
210 return;
211 }
212 const uint8_t* p_codec_info = codec_info;
213 min_bitpool = A2DP_GetMinBitpoolSbc(p_codec_info);
214 max_bitpool = A2DP_GetMaxBitpoolSbc(p_codec_info);
215
216 // The feeding parameters
217 tA2DP_FEEDING_PARAMS* p_feeding_params = &a2dp_sbc_encoder_cb.feeding_params;
218 p_feeding_params->sample_rate = A2DP_GetTrackSampleRateSbc(p_codec_info);
219 p_feeding_params->bits_per_sample =
220 a2dp_codec_config->getAudioBitsPerSample();
221 p_feeding_params->channel_count = A2DP_GetTrackChannelCountSbc(p_codec_info);
222 LOG_DEBUG(LOG_TAG, "%s: sample_rate=%u bits_per_sample=%u channel_count=%u",
223 __func__, p_feeding_params->sample_rate,
224 p_feeding_params->bits_per_sample, p_feeding_params->channel_count);
225 a2dp_sbc_feeding_reset();
226
227 // The codec parameters
228 p_encoder_params->s16ChannelMode = A2DP_GetChannelModeCodeSbc(p_codec_info);
229 p_encoder_params->s16NumOfSubBands =
230 A2DP_GetNumberOfSubbandsSbc(p_codec_info);
231 p_encoder_params->s16NumOfBlocks = A2DP_GetNumberOfBlocksSbc(p_codec_info);
232 p_encoder_params->s16AllocationMethod =
233 A2DP_GetAllocationMethodCodeSbc(p_codec_info);
234 p_encoder_params->s16SamplingFreq =
235 A2DP_GetSamplingFrequencyCodeSbc(p_codec_info);
236 p_encoder_params->s16NumOfChannels =
237 A2DP_GetTrackChannelCountSbc(p_codec_info);
238
239 // Reset invalid parameters
240 if (!p_encoder_params->s16NumOfSubBands) {
241 LOG_WARN(LOG_TAG, "%s: SubBands are set to 0, resetting to max (%d)",
242 __func__, SBC_MAX_NUM_OF_SUBBANDS);
243 p_encoder_params->s16NumOfSubBands = SBC_MAX_NUM_OF_SUBBANDS;
244 }
245 if (!p_encoder_params->s16NumOfBlocks) {
246 LOG_WARN(LOG_TAG, "%s: Blocks are set to 0, resetting to max (%d)",
247 __func__, SBC_MAX_NUM_OF_BLOCKS);
248 p_encoder_params->s16NumOfBlocks = SBC_MAX_NUM_OF_BLOCKS;
249 }
250 if (!p_encoder_params->s16NumOfChannels) {
251 LOG_WARN(LOG_TAG, "%s: Channels are set to 0, resetting to max (%d)",
252 __func__, SBC_MAX_NUM_OF_CHANNELS);
253 p_encoder_params->s16NumOfChannels = SBC_MAX_NUM_OF_CHANNELS;
254 }
255
256 uint16_t mtu_size = A2DP_SBC_BUFFER_SIZE - A2DP_SBC_OFFSET - sizeof(BT_HDR);
257 if (mtu_size < peer_mtu) {
258 a2dp_sbc_encoder_cb.TxAaMtuSize = mtu_size;
259 } else {
260 a2dp_sbc_encoder_cb.TxAaMtuSize = peer_mtu;
261 }
262
263 if (p_encoder_params->s16SamplingFreq == SBC_sf16000)
264 s16SamplingFreq = 16000;
265 else if (p_encoder_params->s16SamplingFreq == SBC_sf32000)
266 s16SamplingFreq = 32000;
267 else if (p_encoder_params->s16SamplingFreq == SBC_sf44100)
268 s16SamplingFreq = 44100;
269 else
270 s16SamplingFreq = 48000;
271
272 // Set the initial target bit rate
273 p_encoder_params->u16BitRate = a2dp_sbc_source_rate();
274
275 LOG_DEBUG(LOG_TAG, "%s: MTU=%d, peer_mtu=%d min_bitpool=%d max_bitpool=%d",
276 __func__, a2dp_sbc_encoder_cb.TxAaMtuSize, peer_mtu, min_bitpool,
277 max_bitpool);
278 LOG_DEBUG(LOG_TAG,
279 "%s: ChannelMode=%d, NumOfSubBands=%d, NumOfBlocks=%d, "
280 "AllocationMethod=%d, BitRate=%d, SamplingFreq=%d BitPool=%d",
281 __func__, p_encoder_params->s16ChannelMode,
282 p_encoder_params->s16NumOfSubBands,
283 p_encoder_params->s16NumOfBlocks,
284 p_encoder_params->s16AllocationMethod, p_encoder_params->u16BitRate,
285 s16SamplingFreq, p_encoder_params->s16BitPool);
286
287 do {
288 if ((p_encoder_params->s16ChannelMode == SBC_JOINT_STEREO) ||
289 (p_encoder_params->s16ChannelMode == SBC_STEREO)) {
290 s16BitPool = (int16_t)((p_encoder_params->u16BitRate *
291 p_encoder_params->s16NumOfSubBands * 1000 /
292 s16SamplingFreq) -
293 ((32 + (4 * p_encoder_params->s16NumOfSubBands *
294 p_encoder_params->s16NumOfChannels) +
295 ((p_encoder_params->s16ChannelMode - 2) *
296 p_encoder_params->s16NumOfSubBands)) /
297 p_encoder_params->s16NumOfBlocks));
298
299 s16FrameLen = 4 +
300 (4 * p_encoder_params->s16NumOfSubBands *
301 p_encoder_params->s16NumOfChannels) /
302 8 +
303 (((p_encoder_params->s16ChannelMode - 2) *
304 p_encoder_params->s16NumOfSubBands) +
305 (p_encoder_params->s16NumOfBlocks * s16BitPool)) /
306 8;
307
308 s16BitRate = (8 * s16FrameLen * s16SamplingFreq) /
309 (p_encoder_params->s16NumOfSubBands *
310 p_encoder_params->s16NumOfBlocks * 1000);
311
312 if (s16BitRate > p_encoder_params->u16BitRate) s16BitPool--;
313
314 if (p_encoder_params->s16NumOfSubBands == 8)
315 s16BitPool = (s16BitPool > 255) ? 255 : s16BitPool;
316 else
317 s16BitPool = (s16BitPool > 128) ? 128 : s16BitPool;
318 } else {
319 s16BitPool =
320 (int16_t)(((p_encoder_params->s16NumOfSubBands *
321 p_encoder_params->u16BitRate * 1000) /
322 (s16SamplingFreq * p_encoder_params->s16NumOfChannels)) -
323 (((32 / p_encoder_params->s16NumOfChannels) +
324 (4 * p_encoder_params->s16NumOfSubBands)) /
325 p_encoder_params->s16NumOfBlocks));
326
327 p_encoder_params->s16BitPool =
328 (s16BitPool > (16 * p_encoder_params->s16NumOfSubBands))
329 ? (16 * p_encoder_params->s16NumOfSubBands)
330 : s16BitPool;
331 }
332
333 if (s16BitPool < 0) s16BitPool = 0;
334
335 LOG_DEBUG(LOG_TAG, "%s: bitpool candidate: %d (%d kbps)", __func__,
336 s16BitPool, p_encoder_params->u16BitRate);
337
338 if (s16BitPool > max_bitpool) {
339 LOG_DEBUG(LOG_TAG, "%s: computed bitpool too large (%d)", __func__,
340 s16BitPool);
341 /* Decrease bitrate */
342 p_encoder_params->u16BitRate -= A2DP_SBC_BITRATE_STEP;
343 /* Record that we have decreased the bitrate */
344 protect |= 1;
345 } else if (s16BitPool < min_bitpool) {
346 LOG_WARN(LOG_TAG, "%s: computed bitpool too small (%d)", __func__,
347 s16BitPool);
348
349 /* Increase bitrate */
350 uint16_t previous_u16BitRate = p_encoder_params->u16BitRate;
351 p_encoder_params->u16BitRate += A2DP_SBC_BITRATE_STEP;
352 /* Record that we have increased the bitrate */
353 protect |= 2;
354 /* Check over-flow */
355 if (p_encoder_params->u16BitRate < previous_u16BitRate) protect |= 3;
356 } else {
357 break;
358 }
359 /* In case we have already increased and decreased the bitrate, just stop */
360 if (protect == 3) {
361 LOG_ERROR(LOG_TAG, "%s: could not find bitpool in range", __func__);
362 break;
363 }
364 } while (true);
365
366 /* Finally update the bitpool in the encoder structure */
367 p_encoder_params->s16BitPool = s16BitPool;
368
369 LOG_DEBUG(LOG_TAG, "%s: final bit rate %d, final bit pool %d", __func__,
370 p_encoder_params->u16BitRate, p_encoder_params->s16BitPool);
371
372 /* Reset the SBC encoder */
373 SBC_Encoder_Init(&a2dp_sbc_encoder_cb.sbc_encoder_params);
374 a2dp_sbc_encoder_cb.tx_sbc_frames = calculate_max_frames_per_packet();
375 }
376
a2dp_sbc_encoder_cleanup(void)377 void a2dp_sbc_encoder_cleanup(void) {
378 memset(&a2dp_sbc_encoder_cb, 0, sizeof(a2dp_sbc_encoder_cb));
379 }
380
a2dp_sbc_feeding_reset(void)381 void a2dp_sbc_feeding_reset(void) {
382 /* By default, just clear the entire state */
383 memset(&a2dp_sbc_encoder_cb.feeding_state, 0,
384 sizeof(a2dp_sbc_encoder_cb.feeding_state));
385
386 a2dp_sbc_encoder_cb.feeding_state.bytes_per_tick =
387 (a2dp_sbc_encoder_cb.feeding_params.sample_rate *
388 a2dp_sbc_encoder_cb.feeding_params.bits_per_sample / 8 *
389 a2dp_sbc_encoder_cb.feeding_params.channel_count *
390 A2DP_SBC_ENCODER_INTERVAL_MS) /
391 1000;
392
393 LOG_DEBUG(LOG_TAG, "%s: PCM bytes per tick %u", __func__,
394 a2dp_sbc_encoder_cb.feeding_state.bytes_per_tick);
395 }
396
a2dp_sbc_feeding_flush(void)397 void a2dp_sbc_feeding_flush(void) {
398 a2dp_sbc_encoder_cb.feeding_state.counter = 0;
399 a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue = 0;
400 }
401
a2dp_sbc_get_encoder_interval_ms(void)402 period_ms_t a2dp_sbc_get_encoder_interval_ms(void) {
403 return A2DP_SBC_ENCODER_INTERVAL_MS;
404 }
405
a2dp_sbc_send_frames(uint64_t timestamp_us)406 void a2dp_sbc_send_frames(uint64_t timestamp_us) {
407 uint8_t nb_frame = 0;
408 uint8_t nb_iterations = 0;
409
410 a2dp_sbc_get_num_frame_iteration(&nb_iterations, &nb_frame, timestamp_us);
411 LOG_VERBOSE(LOG_TAG, "%s: Sending %d frames per iteration, %d iterations",
412 __func__, nb_frame, nb_iterations);
413 if (nb_frame == 0) return;
414
415 for (uint8_t counter = 0; counter < nb_iterations; counter++) {
416 // Transcode frame and enqueue
417 a2dp_sbc_encode_frames(nb_frame);
418 }
419 }
420
421 // Obtains the number of frames to send and number of iterations
422 // to be used. |num_of_iterations| and |num_of_frames| parameters
423 // are used as output param for returning the respective values.
a2dp_sbc_get_num_frame_iteration(uint8_t * num_of_iterations,uint8_t * num_of_frames,uint64_t timestamp_us)424 static void a2dp_sbc_get_num_frame_iteration(uint8_t* num_of_iterations,
425 uint8_t* num_of_frames,
426 uint64_t timestamp_us) {
427 uint8_t nof = 0;
428 uint8_t noi = 1;
429
430 uint32_t projected_nof = 0;
431 uint32_t pcm_bytes_per_frame =
432 a2dp_sbc_encoder_cb.sbc_encoder_params.s16NumOfSubBands *
433 a2dp_sbc_encoder_cb.sbc_encoder_params.s16NumOfBlocks *
434 a2dp_sbc_encoder_cb.feeding_params.channel_count *
435 a2dp_sbc_encoder_cb.feeding_params.bits_per_sample / 8;
436 LOG_VERBOSE(LOG_TAG, "%s: pcm_bytes_per_frame %u", __func__,
437 pcm_bytes_per_frame);
438
439 uint32_t us_this_tick = A2DP_SBC_ENCODER_INTERVAL_MS * 1000;
440 uint64_t now_us = timestamp_us;
441 if (a2dp_sbc_encoder_cb.feeding_state.last_frame_us != 0)
442 us_this_tick = (now_us - a2dp_sbc_encoder_cb.feeding_state.last_frame_us);
443 a2dp_sbc_encoder_cb.feeding_state.last_frame_us = now_us;
444
445 a2dp_sbc_encoder_cb.feeding_state.counter +=
446 a2dp_sbc_encoder_cb.feeding_state.bytes_per_tick * us_this_tick /
447 (A2DP_SBC_ENCODER_INTERVAL_MS * 1000);
448
449 /* Calculate the number of frames pending for this media tick */
450 projected_nof =
451 a2dp_sbc_encoder_cb.feeding_state.counter / pcm_bytes_per_frame;
452 // Update the stats
453 a2dp_sbc_encoder_cb.stats.media_read_total_expected_frames += projected_nof;
454
455 if (projected_nof > MAX_PCM_FRAME_NUM_PER_TICK) {
456 LOG_WARN(LOG_TAG, "%s: limiting frames to be sent from %d to %d", __func__,
457 projected_nof, MAX_PCM_FRAME_NUM_PER_TICK);
458
459 // Update the stats
460 size_t delta = projected_nof - MAX_PCM_FRAME_NUM_PER_TICK;
461 a2dp_sbc_encoder_cb.stats.media_read_total_dropped_frames += delta;
462
463 projected_nof = MAX_PCM_FRAME_NUM_PER_TICK;
464 }
465
466 LOG_VERBOSE(LOG_TAG, "%s: frames for available PCM data %u", __func__,
467 projected_nof);
468
469 if (a2dp_sbc_encoder_cb.is_peer_edr) {
470 if (!a2dp_sbc_encoder_cb.tx_sbc_frames) {
471 LOG_ERROR(LOG_TAG, "%s: tx_sbc_frames not updated, update from here",
472 __func__);
473 a2dp_sbc_encoder_cb.tx_sbc_frames = calculate_max_frames_per_packet();
474 }
475
476 nof = a2dp_sbc_encoder_cb.tx_sbc_frames;
477 if (!nof) {
478 LOG_ERROR(LOG_TAG,
479 "%s: number of frames not updated, set calculated values",
480 __func__);
481 nof = projected_nof;
482 noi = 1;
483 } else {
484 if (nof < projected_nof) {
485 noi = projected_nof / nof; // number of iterations would vary
486 if (noi > A2DP_SBC_MAX_PCM_ITER_NUM_PER_TICK) {
487 LOG_ERROR(LOG_TAG, "%s: Audio Congestion (iterations:%d > max (%d))",
488 __func__, noi, A2DP_SBC_MAX_PCM_ITER_NUM_PER_TICK);
489 noi = A2DP_SBC_MAX_PCM_ITER_NUM_PER_TICK;
490 a2dp_sbc_encoder_cb.feeding_state.counter =
491 noi * nof * pcm_bytes_per_frame;
492 }
493 projected_nof = nof;
494 } else {
495 noi = 1; // number of iterations is 1
496 LOG_VERBOSE(LOG_TAG, "%s: reducing frames for available PCM data",
497 __func__);
498 nof = projected_nof;
499 }
500 }
501 } else {
502 // For BR cases nof will be same as the value retrieved at projected_nof
503 LOG_VERBOSE(LOG_TAG, "%s: headset BR, number of frames %u", __func__, nof);
504 if (projected_nof > MAX_PCM_FRAME_NUM_PER_TICK) {
505 LOG_ERROR(LOG_TAG, "%s: Audio Congestion (frames: %d > max (%d))",
506 __func__, projected_nof, MAX_PCM_FRAME_NUM_PER_TICK);
507
508 // Update the stats
509 size_t delta = projected_nof - MAX_PCM_FRAME_NUM_PER_TICK;
510 a2dp_sbc_encoder_cb.stats.media_read_total_dropped_frames += delta;
511
512 projected_nof = MAX_PCM_FRAME_NUM_PER_TICK;
513 a2dp_sbc_encoder_cb.feeding_state.counter =
514 noi * projected_nof * pcm_bytes_per_frame;
515 }
516 nof = projected_nof;
517 }
518 a2dp_sbc_encoder_cb.feeding_state.counter -= noi * nof * pcm_bytes_per_frame;
519 LOG_VERBOSE(LOG_TAG, "%s: effective num of frames %u, iterations %u",
520 __func__, nof, noi);
521
522 *num_of_frames = nof;
523 *num_of_iterations = noi;
524 }
525
a2dp_sbc_encode_frames(uint8_t nb_frame)526 static void a2dp_sbc_encode_frames(uint8_t nb_frame) {
527 SBC_ENC_PARAMS* p_encoder_params = &a2dp_sbc_encoder_cb.sbc_encoder_params;
528 uint8_t remain_nb_frame = nb_frame;
529 uint16_t blocm_x_subband =
530 p_encoder_params->s16NumOfSubBands * p_encoder_params->s16NumOfBlocks;
531
532 uint8_t last_frame_len = 0;
533
534 while (nb_frame) {
535 BT_HDR* p_buf = (BT_HDR*)osi_malloc(A2DP_SBC_BUFFER_SIZE);
536 uint32_t bytes_read = 0;
537
538 p_buf->offset = A2DP_SBC_OFFSET;
539 p_buf->len = 0;
540 p_buf->layer_specific = 0;
541 a2dp_sbc_encoder_cb.stats.media_read_total_expected_packets++;
542
543 do {
544 /* Fill allocated buffer with 0 */
545 memset(a2dp_sbc_encoder_cb.pcmBuffer, 0,
546 blocm_x_subband * p_encoder_params->s16NumOfChannels);
547 //
548 // Read the PCM data and encode it. If necessary, upsample the data.
549 //
550 uint32_t num_bytes = 0;
551 if (a2dp_sbc_read_feeding(&num_bytes)) {
552 uint8_t* output = (uint8_t*)(p_buf + 1) + p_buf->offset + p_buf->len;
553 int16_t* input = a2dp_sbc_encoder_cb.pcmBuffer;
554 uint16_t output_len = SBC_Encode(p_encoder_params, input, output);
555 last_frame_len = output_len;
556
557 /* Update SBC frame length */
558 p_buf->len += output_len;
559 nb_frame--;
560 p_buf->layer_specific++;
561
562 bytes_read += num_bytes;
563 } else {
564 LOG_WARN(LOG_TAG, "%s: underflow %d, %d", __func__, nb_frame,
565 a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue);
566 a2dp_sbc_encoder_cb.feeding_state.counter +=
567 nb_frame * p_encoder_params->s16NumOfSubBands *
568 p_encoder_params->s16NumOfBlocks *
569 a2dp_sbc_encoder_cb.feeding_params.channel_count *
570 a2dp_sbc_encoder_cb.feeding_params.bits_per_sample / 8;
571 /* no more pcm to read */
572 nb_frame = 0;
573 }
574 } while (
575 ((p_buf->len + last_frame_len) < a2dp_sbc_encoder_cb.TxAaMtuSize) &&
576 (p_buf->layer_specific < 0x0F) && nb_frame);
577
578 if (p_buf->len) {
579 /*
580 * Timestamp of the media packet header represent the TS of the
581 * first SBC frame, i.e the timestamp before including this frame.
582 */
583 *((uint32_t*)(p_buf + 1)) = a2dp_sbc_encoder_cb.timestamp;
584
585 a2dp_sbc_encoder_cb.timestamp += p_buf->layer_specific * blocm_x_subband;
586
587 uint8_t done_nb_frame = remain_nb_frame - nb_frame;
588 remain_nb_frame = nb_frame;
589 if (!a2dp_sbc_encoder_cb.enqueue_callback(p_buf, done_nb_frame,
590 bytes_read))
591 return;
592 } else {
593 a2dp_sbc_encoder_cb.stats.media_read_total_dropped_packets++;
594 osi_free(p_buf);
595 }
596 }
597 }
598
a2dp_sbc_read_feeding(uint32_t * bytes_read)599 static bool a2dp_sbc_read_feeding(uint32_t* bytes_read) {
600 SBC_ENC_PARAMS* p_encoder_params = &a2dp_sbc_encoder_cb.sbc_encoder_params;
601 uint16_t blocm_x_subband =
602 p_encoder_params->s16NumOfSubBands * p_encoder_params->s16NumOfBlocks;
603 uint32_t read_size;
604 uint32_t sbc_sampling = 48000;
605 uint32_t src_samples;
606 uint16_t bytes_needed = blocm_x_subband * p_encoder_params->s16NumOfChannels *
607 a2dp_sbc_encoder_cb.feeding_params.bits_per_sample /
608 8;
609 static uint16_t up_sampled_buffer[SBC_MAX_NUM_FRAME * SBC_MAX_NUM_OF_BLOCKS *
610 SBC_MAX_NUM_OF_CHANNELS *
611 SBC_MAX_NUM_OF_SUBBANDS * 2];
612 static uint16_t read_buffer[SBC_MAX_NUM_FRAME * SBC_MAX_NUM_OF_BLOCKS *
613 SBC_MAX_NUM_OF_CHANNELS *
614 SBC_MAX_NUM_OF_SUBBANDS];
615 uint32_t src_size_used;
616 uint32_t dst_size_used;
617 bool fract_needed;
618 int32_t fract_max;
619 int32_t fract_threshold;
620 uint32_t nb_byte_read;
621
622 /* Get the SBC sampling rate */
623 switch (p_encoder_params->s16SamplingFreq) {
624 case SBC_sf48000:
625 sbc_sampling = 48000;
626 break;
627 case SBC_sf44100:
628 sbc_sampling = 44100;
629 break;
630 case SBC_sf32000:
631 sbc_sampling = 32000;
632 break;
633 case SBC_sf16000:
634 sbc_sampling = 16000;
635 break;
636 }
637
638 a2dp_sbc_encoder_cb.stats.media_read_total_expected_reads_count++;
639 if (sbc_sampling == a2dp_sbc_encoder_cb.feeding_params.sample_rate) {
640 read_size =
641 bytes_needed - a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue;
642 a2dp_sbc_encoder_cb.stats.media_read_total_expected_read_bytes += read_size;
643 nb_byte_read = a2dp_sbc_encoder_cb.read_callback(
644 ((uint8_t*)a2dp_sbc_encoder_cb.pcmBuffer) +
645 a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue,
646 read_size);
647 a2dp_sbc_encoder_cb.stats.media_read_total_actual_read_bytes +=
648 nb_byte_read;
649
650 *bytes_read = nb_byte_read;
651 if (nb_byte_read != read_size) {
652 a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue += nb_byte_read;
653 return false;
654 }
655 a2dp_sbc_encoder_cb.stats.media_read_total_actual_reads_count++;
656 a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue = 0;
657 return true;
658 }
659
660 /*
661 * Some Feeding PCM frequencies require to split the number of sample
662 * to read.
663 * E.g 128 / 6 = 21.3333 => read 22 and 21 and 21 => max = 2; threshold = 0
664 */
665 fract_needed = false; /* Default */
666 switch (a2dp_sbc_encoder_cb.feeding_params.sample_rate) {
667 case 32000:
668 case 8000:
669 fract_needed = true;
670 fract_max = 2; /* 0, 1 and 2 */
671 fract_threshold = 0; /* Add one for the first */
672 break;
673 case 16000:
674 fract_needed = true;
675 fract_max = 2; /* 0, 1 and 2 */
676 fract_threshold = 1; /* Add one for the first two frames*/
677 break;
678 }
679
680 /* Compute number of sample to read from source */
681 src_samples = blocm_x_subband;
682 src_samples *= a2dp_sbc_encoder_cb.feeding_params.sample_rate;
683 src_samples /= sbc_sampling;
684
685 /* The previous division may have a remainder not null */
686 if (fract_needed) {
687 if (a2dp_sbc_encoder_cb.feeding_state.aa_feed_counter <= fract_threshold) {
688 src_samples++; /* for every read before threshold add one sample */
689 }
690
691 /* do nothing if counter >= threshold */
692 a2dp_sbc_encoder_cb.feeding_state.aa_feed_counter++; /* one more read */
693 if (a2dp_sbc_encoder_cb.feeding_state.aa_feed_counter > fract_max) {
694 a2dp_sbc_encoder_cb.feeding_state.aa_feed_counter = 0;
695 }
696 }
697
698 /* Compute number of bytes to read from source */
699 read_size = src_samples;
700 read_size *= a2dp_sbc_encoder_cb.feeding_params.channel_count;
701 read_size *= (a2dp_sbc_encoder_cb.feeding_params.bits_per_sample / 8);
702 a2dp_sbc_encoder_cb.stats.media_read_total_expected_read_bytes += read_size;
703
704 /* Read Data from UIPC channel */
705 nb_byte_read =
706 a2dp_sbc_encoder_cb.read_callback((uint8_t*)read_buffer, read_size);
707 a2dp_sbc_encoder_cb.stats.media_read_total_actual_read_bytes += nb_byte_read;
708
709 if (nb_byte_read < read_size) {
710 if (nb_byte_read == 0) return false;
711
712 /* Fill the unfilled part of the read buffer with silence (0) */
713 memset(((uint8_t*)read_buffer) + nb_byte_read, 0, read_size - nb_byte_read);
714 nb_byte_read = read_size;
715 }
716 a2dp_sbc_encoder_cb.stats.media_read_total_actual_reads_count++;
717
718 /* Initialize PCM up-sampling engine */
719 a2dp_sbc_init_up_sample(a2dp_sbc_encoder_cb.feeding_params.sample_rate,
720 sbc_sampling,
721 a2dp_sbc_encoder_cb.feeding_params.bits_per_sample,
722 a2dp_sbc_encoder_cb.feeding_params.channel_count);
723
724 /*
725 * Re-sample the read buffer.
726 * The output PCM buffer will be stereo, 16 bit per sample.
727 */
728 dst_size_used = a2dp_sbc_up_sample(
729 (uint8_t*)read_buffer,
730 (uint8_t*)up_sampled_buffer +
731 a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue,
732 nb_byte_read, sizeof(up_sampled_buffer) -
733 a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue,
734 &src_size_used);
735
736 /* update the residue */
737 a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue += dst_size_used;
738
739 /* only copy the pcm sample when we have up-sampled enough PCM */
740 if (a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue < bytes_needed)
741 return false;
742
743 /* Copy the output pcm samples in SBC encoding buffer */
744 memcpy((uint8_t*)a2dp_sbc_encoder_cb.pcmBuffer, (uint8_t*)up_sampled_buffer,
745 bytes_needed);
746 /* update the residue */
747 a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue -= bytes_needed;
748
749 if (a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue != 0) {
750 memcpy((uint8_t*)up_sampled_buffer,
751 (uint8_t*)up_sampled_buffer + bytes_needed,
752 a2dp_sbc_encoder_cb.feeding_state.aa_feed_residue);
753 }
754 return true;
755 }
756
calculate_max_frames_per_packet(void)757 static uint8_t calculate_max_frames_per_packet(void) {
758 uint16_t effective_mtu_size = a2dp_sbc_encoder_cb.TxAaMtuSize;
759 SBC_ENC_PARAMS* p_encoder_params = &a2dp_sbc_encoder_cb.sbc_encoder_params;
760 uint16_t result = 0;
761 uint32_t frame_len;
762
763 LOG_VERBOSE(LOG_TAG, "%s: original AVDTP MTU size: %d", __func__,
764 a2dp_sbc_encoder_cb.TxAaMtuSize);
765 if (a2dp_sbc_encoder_cb.is_peer_edr &&
766 !a2dp_sbc_encoder_cb.peer_supports_3mbps) {
767 // This condition would be satisfied only if the remote device is
768 // EDR and supports only 2 Mbps, but the effective AVDTP MTU size
769 // exceeds the 2DH5 packet size.
770 LOG_VERBOSE(LOG_TAG,
771 "%s: The remote device is EDR but does not support 3 Mbps",
772 __func__);
773
774 if (effective_mtu_size > MAX_2MBPS_AVDTP_MTU) {
775 LOG_WARN(LOG_TAG, "%s: Restricting AVDTP MTU size to %d", __func__,
776 MAX_2MBPS_AVDTP_MTU);
777 effective_mtu_size = MAX_2MBPS_AVDTP_MTU;
778 a2dp_sbc_encoder_cb.TxAaMtuSize = effective_mtu_size;
779 }
780 }
781
782 if (!p_encoder_params->s16NumOfSubBands) {
783 LOG_ERROR(LOG_TAG, "%s: SubBands are set to 0, resetting to %d", __func__,
784 SBC_MAX_NUM_OF_SUBBANDS);
785 p_encoder_params->s16NumOfSubBands = SBC_MAX_NUM_OF_SUBBANDS;
786 }
787 if (!p_encoder_params->s16NumOfBlocks) {
788 LOG_ERROR(LOG_TAG, "%s: Blocks are set to 0, resetting to %d", __func__,
789 SBC_MAX_NUM_OF_BLOCKS);
790 p_encoder_params->s16NumOfBlocks = SBC_MAX_NUM_OF_BLOCKS;
791 }
792 if (!p_encoder_params->s16NumOfChannels) {
793 LOG_ERROR(LOG_TAG, "%s: Channels are set to 0, resetting to %d", __func__,
794 SBC_MAX_NUM_OF_CHANNELS);
795 p_encoder_params->s16NumOfChannels = SBC_MAX_NUM_OF_CHANNELS;
796 }
797
798 frame_len = a2dp_sbc_frame_length();
799
800 LOG_VERBOSE(LOG_TAG, "%s: Effective Tx MTU to be considered: %d", __func__,
801 effective_mtu_size);
802
803 switch (p_encoder_params->s16SamplingFreq) {
804 case SBC_sf44100:
805 if (frame_len == 0) {
806 LOG_ERROR(LOG_TAG,
807 "%s: Calculating frame length, resetting it to default %d",
808 __func__, A2DP_SBC_MAX_HQ_FRAME_SIZE_44_1);
809 frame_len = A2DP_SBC_MAX_HQ_FRAME_SIZE_44_1;
810 }
811 result = (effective_mtu_size - A2DP_HDR_SIZE) / frame_len;
812 LOG_VERBOSE(LOG_TAG, "%s: Max number of SBC frames: %d", __func__,
813 result);
814 break;
815
816 case SBC_sf48000:
817 if (frame_len == 0) {
818 LOG_ERROR(LOG_TAG,
819 "%s: Calculating frame length, resetting it to default %d",
820 __func__, A2DP_SBC_MAX_HQ_FRAME_SIZE_48);
821 frame_len = A2DP_SBC_MAX_HQ_FRAME_SIZE_48;
822 }
823 result = (effective_mtu_size - A2DP_HDR_SIZE) / frame_len;
824 LOG_VERBOSE(LOG_TAG, "%s: Max number of SBC frames: %d", __func__,
825 result);
826 break;
827
828 default:
829 LOG_ERROR(LOG_TAG, "%s: Max number of SBC frames: %d", __func__, result);
830 break;
831 }
832 return result;
833 }
834
a2dp_sbc_source_rate()835 static uint16_t a2dp_sbc_source_rate() {
836 uint16_t rate = A2DP_SBC_DEFAULT_BITRATE;
837
838 /* restrict bitrate if a2dp link is non-edr */
839 if (!a2dp_sbc_encoder_cb.is_peer_edr) {
840 rate = A2DP_SBC_NON_EDR_MAX_RATE;
841 LOG_VERBOSE(LOG_TAG, "%s: non-edr a2dp sink detected, restrict rate to %d",
842 __func__, rate);
843 }
844
845 return rate;
846 }
847
a2dp_sbc_frame_length(void)848 static uint32_t a2dp_sbc_frame_length(void) {
849 SBC_ENC_PARAMS* p_encoder_params = &a2dp_sbc_encoder_cb.sbc_encoder_params;
850 uint32_t frame_len = 0;
851
852 LOG_VERBOSE(LOG_TAG,
853 "%s: channel mode: %d, sub-band: %d, number of block: %d, "
854 "bitpool: %d, sampling frequency: %d, num channels: %d",
855 __func__, p_encoder_params->s16ChannelMode,
856 p_encoder_params->s16NumOfSubBands,
857 p_encoder_params->s16NumOfBlocks, p_encoder_params->s16BitPool,
858 p_encoder_params->s16SamplingFreq,
859 p_encoder_params->s16NumOfChannels);
860
861 switch (p_encoder_params->s16ChannelMode) {
862 case SBC_MONO:
863 /* FALLTHROUGH */
864 case SBC_DUAL:
865 frame_len = A2DP_SBC_FRAME_HEADER_SIZE_BYTES +
866 ((uint32_t)(A2DP_SBC_SCALE_FACTOR_BITS *
867 p_encoder_params->s16NumOfSubBands *
868 p_encoder_params->s16NumOfChannels) /
869 CHAR_BIT) +
870 ((uint32_t)(p_encoder_params->s16NumOfBlocks *
871 p_encoder_params->s16NumOfChannels *
872 p_encoder_params->s16BitPool) /
873 CHAR_BIT);
874 break;
875 case SBC_STEREO:
876 frame_len = A2DP_SBC_FRAME_HEADER_SIZE_BYTES +
877 ((uint32_t)(A2DP_SBC_SCALE_FACTOR_BITS *
878 p_encoder_params->s16NumOfSubBands *
879 p_encoder_params->s16NumOfChannels) /
880 CHAR_BIT) +
881 ((uint32_t)(p_encoder_params->s16NumOfBlocks *
882 p_encoder_params->s16BitPool) /
883 CHAR_BIT);
884 break;
885 case SBC_JOINT_STEREO:
886 frame_len = A2DP_SBC_FRAME_HEADER_SIZE_BYTES +
887 ((uint32_t)(A2DP_SBC_SCALE_FACTOR_BITS *
888 p_encoder_params->s16NumOfSubBands *
889 p_encoder_params->s16NumOfChannels) /
890 CHAR_BIT) +
891 ((uint32_t)(p_encoder_params->s16NumOfSubBands +
892 (p_encoder_params->s16NumOfBlocks *
893 p_encoder_params->s16BitPool)) /
894 CHAR_BIT);
895 break;
896 default:
897 LOG_VERBOSE(LOG_TAG, "%s: Invalid channel number: %d", __func__,
898 p_encoder_params->s16ChannelMode);
899 break;
900 }
901 LOG_VERBOSE(LOG_TAG, "%s: calculated frame length: %d", __func__, frame_len);
902 return frame_len;
903 }
904
a2dp_sbc_get_bitrate()905 uint32_t a2dp_sbc_get_bitrate() {
906 SBC_ENC_PARAMS* p_encoder_params = &a2dp_sbc_encoder_cb.sbc_encoder_params;
907 LOG_DEBUG(LOG_TAG, "%s: bit rate %d ", __func__,
908 p_encoder_params->u16BitRate);
909 return p_encoder_params->u16BitRate * 1000;
910 }
911
encoderIntervalMs() const912 period_ms_t A2dpCodecConfigSbcSource::encoderIntervalMs() const {
913 return a2dp_sbc_get_encoder_interval_ms();
914 }
915
getEffectiveMtu() const916 int A2dpCodecConfigSbcSource::getEffectiveMtu() const {
917 return a2dp_sbc_encoder_cb.TxAaMtuSize;
918 }
919
debug_codec_dump(int fd)920 void A2dpCodecConfigSbcSource::debug_codec_dump(int fd) {
921 a2dp_sbc_encoder_stats_t* stats = &a2dp_sbc_encoder_cb.stats;
922
923 A2dpCodecConfig::debug_codec_dump(fd);
924
925 dprintf(fd,
926 " Packet counts (expected/dropped) : %zu / "
927 "%zu\n",
928 stats->media_read_total_expected_packets,
929 stats->media_read_total_dropped_packets);
930
931 dprintf(fd,
932 " PCM read counts (expected/actual) : %zu / "
933 "%zu\n",
934 stats->media_read_total_expected_reads_count,
935 stats->media_read_total_actual_reads_count);
936
937 dprintf(fd,
938 " PCM read bytes (expected/actual) : %zu / "
939 "%zu\n",
940 stats->media_read_total_expected_read_bytes,
941 stats->media_read_total_actual_read_bytes);
942
943 dprintf(fd,
944 " Frames counts (expected/dropped) : %zu / "
945 "%zu\n",
946 stats->media_read_total_expected_frames,
947 stats->media_read_total_dropped_frames);
948 }
949