1 /*
2 * Copyright 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_TAG "a2dp_vendor_aptx_encoder"
18
19 #include "a2dp_vendor_aptx_encoder.h"
20
21 #include <dlfcn.h>
22 #include <inttypes.h>
23 #include <stdio.h>
24 #include <string.h>
25
26 #include "a2dp_vendor.h"
27 #include "a2dp_vendor_aptx.h"
28 #include "bt_common.h"
29 #include "common/time_util.h"
30 #include "osi/include/log.h"
31 #include "osi/include/osi.h"
32
33 //
34 // Encoder for aptX Source Codec
35 //
36
37 //
38 // The aptX encoder shared library, and the functions to use
39 //
40 static const char* APTX_ENCODER_LIB_NAME = "libaptX_encoder.so";
41 static void* aptx_encoder_lib_handle = NULL;
42
43 static const char* APTX_ENCODER_INIT_NAME = "aptxbtenc_init";
44 typedef int (*tAPTX_ENCODER_INIT)(void* state, short endian);
45
46 static const char* APTX_ENCODER_ENCODE_STEREO_NAME = "aptxbtenc_encodestereo";
47 typedef int (*tAPTX_ENCODER_ENCODE_STEREO)(void* state, void* pcmL, void* pcmR,
48 void* buffer);
49
50 static const char* APTX_ENCODER_SIZEOF_PARAMS_NAME = "SizeofAptxbtenc";
51 typedef int (*tAPTX_ENCODER_SIZEOF_PARAMS)(void);
52
53 static tAPTX_ENCODER_INIT aptx_encoder_init_func;
54 static tAPTX_ENCODER_ENCODE_STEREO aptx_encoder_encode_stereo_func;
55 static tAPTX_ENCODER_SIZEOF_PARAMS aptx_encoder_sizeof_params_func;
56
57 // offset
58 #if (BTA_AV_CO_CP_SCMS_T == TRUE)
59 #define A2DP_APTX_OFFSET (AVDT_MEDIA_OFFSET + 1)
60 #else
61 // no RTP header for aptX classic
62 #define A2DP_APTX_OFFSET (AVDT_MEDIA_OFFSET - AVDT_MEDIA_HDR_SIZE)
63 #endif
64
65 #define A2DP_APTX_MAX_PCM_BYTES_PER_READ 4096
66
67 typedef struct {
68 uint64_t sleep_time_ns;
69 uint32_t pcm_reads;
70 uint32_t pcm_bytes_per_read;
71 uint32_t aptx_bytes;
72 uint32_t frame_size_counter;
73 } tAPTX_FRAMING_PARAMS;
74
75 typedef struct {
76 uint64_t session_start_us;
77
78 size_t media_read_total_expected_packets;
79 size_t media_read_total_expected_reads_count;
80 size_t media_read_total_expected_read_bytes;
81
82 size_t media_read_total_dropped_packets;
83 size_t media_read_total_actual_reads_count;
84 size_t media_read_total_actual_read_bytes;
85 } a2dp_aptx_encoder_stats_t;
86
87 typedef struct {
88 a2dp_source_read_callback_t read_callback;
89 a2dp_source_enqueue_callback_t enqueue_callback;
90
91 bool use_SCMS_T;
92 bool is_peer_edr; // True if the peer device supports EDR
93 bool peer_supports_3mbps; // True if the peer device supports 3Mbps EDR
94 uint16_t peer_mtu; // MTU of the A2DP peer
95 uint32_t timestamp; // Timestamp for the A2DP frames
96
97 tA2DP_FEEDING_PARAMS feeding_params;
98 tAPTX_FRAMING_PARAMS framing_params;
99 void* aptx_encoder_state;
100 a2dp_aptx_encoder_stats_t stats;
101 } tA2DP_APTX_ENCODER_CB;
102
103 static tA2DP_APTX_ENCODER_CB a2dp_aptx_encoder_cb;
104
105 static void a2dp_vendor_aptx_encoder_update(uint16_t peer_mtu,
106 A2dpCodecConfig* a2dp_codec_config,
107 bool* p_restart_input,
108 bool* p_restart_output,
109 bool* p_config_updated);
110 static void aptx_init_framing_params(tAPTX_FRAMING_PARAMS* framing_params);
111 static void aptx_update_framing_params(tAPTX_FRAMING_PARAMS* framing_params);
112 static size_t aptx_encode_16bit(tAPTX_FRAMING_PARAMS* framing_params,
113 size_t* data_out_index, uint16_t* data16_in,
114 uint8_t* data_out);
115
A2DP_VendorLoadEncoderAptx(void)116 bool A2DP_VendorLoadEncoderAptx(void) {
117 if (aptx_encoder_lib_handle != NULL) return true; // Already loaded
118
119 // Open the encoder library
120 aptx_encoder_lib_handle = dlopen(APTX_ENCODER_LIB_NAME, RTLD_NOW);
121 if (aptx_encoder_lib_handle == NULL) {
122 LOG_ERROR("%s: cannot open aptX encoder library %s: %s", __func__,
123 APTX_ENCODER_LIB_NAME, dlerror());
124 return false;
125 }
126
127 aptx_encoder_init_func = (tAPTX_ENCODER_INIT)dlsym(aptx_encoder_lib_handle,
128 APTX_ENCODER_INIT_NAME);
129 if (aptx_encoder_init_func == NULL) {
130 LOG_ERROR("%s: cannot find function '%s' in the encoder library: %s",
131 __func__, APTX_ENCODER_INIT_NAME, dlerror());
132 A2DP_VendorUnloadEncoderAptx();
133 return false;
134 }
135
136 aptx_encoder_encode_stereo_func = (tAPTX_ENCODER_ENCODE_STEREO)dlsym(
137 aptx_encoder_lib_handle, APTX_ENCODER_ENCODE_STEREO_NAME);
138 if (aptx_encoder_encode_stereo_func == NULL) {
139 LOG_ERROR("%s: cannot find function '%s' in the encoder library: %s",
140 __func__, APTX_ENCODER_ENCODE_STEREO_NAME, dlerror());
141 A2DP_VendorUnloadEncoderAptx();
142 return false;
143 }
144
145 aptx_encoder_sizeof_params_func = (tAPTX_ENCODER_SIZEOF_PARAMS)dlsym(
146 aptx_encoder_lib_handle, APTX_ENCODER_SIZEOF_PARAMS_NAME);
147 if (aptx_encoder_sizeof_params_func == NULL) {
148 LOG_ERROR("%s: cannot find function '%s' in the encoder library: %s",
149 __func__, APTX_ENCODER_SIZEOF_PARAMS_NAME, dlerror());
150 A2DP_VendorUnloadEncoderAptx();
151 return false;
152 }
153
154 return true;
155 }
156
A2DP_VendorUnloadEncoderAptx(void)157 void A2DP_VendorUnloadEncoderAptx(void) {
158 aptx_encoder_init_func = NULL;
159 aptx_encoder_encode_stereo_func = NULL;
160 aptx_encoder_sizeof_params_func = NULL;
161
162 if (aptx_encoder_lib_handle != NULL) {
163 dlclose(aptx_encoder_lib_handle);
164 aptx_encoder_lib_handle = NULL;
165 }
166 }
167
a2dp_vendor_aptx_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)168 void a2dp_vendor_aptx_encoder_init(
169 const tA2DP_ENCODER_INIT_PEER_PARAMS* p_peer_params,
170 A2dpCodecConfig* a2dp_codec_config,
171 a2dp_source_read_callback_t read_callback,
172 a2dp_source_enqueue_callback_t enqueue_callback) {
173 memset(&a2dp_aptx_encoder_cb, 0, sizeof(a2dp_aptx_encoder_cb));
174
175 a2dp_aptx_encoder_cb.stats.session_start_us =
176 bluetooth::common::time_get_os_boottime_us();
177
178 a2dp_aptx_encoder_cb.read_callback = read_callback;
179 a2dp_aptx_encoder_cb.enqueue_callback = enqueue_callback;
180 a2dp_aptx_encoder_cb.is_peer_edr = p_peer_params->is_peer_edr;
181 a2dp_aptx_encoder_cb.peer_supports_3mbps = p_peer_params->peer_supports_3mbps;
182 a2dp_aptx_encoder_cb.peer_mtu = p_peer_params->peer_mtu;
183 a2dp_aptx_encoder_cb.timestamp = 0;
184
185 /* aptX encoder config */
186 a2dp_aptx_encoder_cb.use_SCMS_T = false; // TODO: should be a parameter
187 #if (BTA_AV_CO_CP_SCMS_T == TRUE)
188 a2dp_aptx_encoder_cb.use_SCMS_T = true;
189 #endif
190
191 a2dp_aptx_encoder_cb.aptx_encoder_state =
192 osi_malloc(aptx_encoder_sizeof_params_func());
193 if (a2dp_aptx_encoder_cb.aptx_encoder_state != NULL) {
194 aptx_encoder_init_func(a2dp_aptx_encoder_cb.aptx_encoder_state, 0);
195 } else {
196 LOG_ERROR("%s: Cannot allocate aptX encoder state", __func__);
197 // TODO: Return an error?
198 }
199
200 // NOTE: Ignore the restart_input / restart_output flags - this initization
201 // happens when the connection is (re)started.
202 bool restart_input = false;
203 bool restart_output = false;
204 bool config_updated = false;
205 a2dp_vendor_aptx_encoder_update(a2dp_aptx_encoder_cb.peer_mtu,
206 a2dp_codec_config, &restart_input,
207 &restart_output, &config_updated);
208 }
209
updateEncoderUserConfig(const tA2DP_ENCODER_INIT_PEER_PARAMS * p_peer_params,bool * p_restart_input,bool * p_restart_output,bool * p_config_updated)210 bool A2dpCodecConfigAptx::updateEncoderUserConfig(
211 const tA2DP_ENCODER_INIT_PEER_PARAMS* p_peer_params, bool* p_restart_input,
212 bool* p_restart_output, bool* p_config_updated) {
213 a2dp_aptx_encoder_cb.is_peer_edr = p_peer_params->is_peer_edr;
214 a2dp_aptx_encoder_cb.peer_supports_3mbps = p_peer_params->peer_supports_3mbps;
215 a2dp_aptx_encoder_cb.peer_mtu = p_peer_params->peer_mtu;
216 a2dp_aptx_encoder_cb.timestamp = 0;
217
218 if (a2dp_aptx_encoder_cb.peer_mtu == 0) {
219 LOG_ERROR(
220 "%s: Cannot update the codec encoder for %s: "
221 "invalid peer MTU",
222 __func__, name().c_str());
223 return false;
224 }
225
226 a2dp_vendor_aptx_encoder_update(a2dp_aptx_encoder_cb.peer_mtu, this,
227 p_restart_input, p_restart_output,
228 p_config_updated);
229 return true;
230 }
231
232 // Update the A2DP aptX encoder.
233 // |peer_mtu| is the peer MTU.
234 // |a2dp_codec_config| is the A2DP codec to use for the update.
a2dp_vendor_aptx_encoder_update(uint16_t peer_mtu,A2dpCodecConfig * a2dp_codec_config,bool * p_restart_input,bool * p_restart_output,bool * p_config_updated)235 static void a2dp_vendor_aptx_encoder_update(uint16_t peer_mtu,
236 A2dpCodecConfig* a2dp_codec_config,
237 bool* p_restart_input,
238 bool* p_restart_output,
239 bool* p_config_updated) {
240 uint8_t codec_info[AVDT_CODEC_SIZE];
241
242 *p_restart_input = false;
243 *p_restart_output = false;
244 *p_config_updated = false;
245 if (!a2dp_codec_config->copyOutOtaCodecConfig(codec_info)) {
246 LOG_ERROR(
247 "%s: Cannot update the codec encoder for %s: "
248 "invalid codec config",
249 __func__, a2dp_codec_config->name().c_str());
250 return;
251 }
252 const uint8_t* p_codec_info = codec_info;
253
254 // The feeding parameters
255 tA2DP_FEEDING_PARAMS* p_feeding_params = &a2dp_aptx_encoder_cb.feeding_params;
256 p_feeding_params->sample_rate =
257 A2DP_VendorGetTrackSampleRateAptx(p_codec_info);
258 p_feeding_params->bits_per_sample =
259 a2dp_codec_config->getAudioBitsPerSample();
260 p_feeding_params->channel_count =
261 A2DP_VendorGetTrackChannelCountAptx(p_codec_info);
262 LOG_INFO("%s: sample_rate=%u bits_per_sample=%u channel_count=%u", __func__,
263 p_feeding_params->sample_rate, p_feeding_params->bits_per_sample,
264 p_feeding_params->channel_count);
265 a2dp_vendor_aptx_feeding_reset();
266 }
267
a2dp_vendor_aptx_encoder_cleanup(void)268 void a2dp_vendor_aptx_encoder_cleanup(void) {
269 osi_free(a2dp_aptx_encoder_cb.aptx_encoder_state);
270 memset(&a2dp_aptx_encoder_cb, 0, sizeof(a2dp_aptx_encoder_cb));
271 }
272
273 //
274 // Initialize the framing parameters, and set those that don't change
275 // while streaming (e.g., 'sleep_time_ns').
276 //
aptx_init_framing_params(tAPTX_FRAMING_PARAMS * framing_params)277 static void aptx_init_framing_params(tAPTX_FRAMING_PARAMS* framing_params) {
278 framing_params->sleep_time_ns = 0;
279 framing_params->pcm_reads = 0;
280 framing_params->pcm_bytes_per_read = 0;
281 framing_params->aptx_bytes = 0;
282 framing_params->frame_size_counter = 0;
283
284 if (a2dp_aptx_encoder_cb.feeding_params.sample_rate == 48000) {
285 if (a2dp_aptx_encoder_cb.use_SCMS_T) {
286 framing_params->sleep_time_ns = 13000000;
287 } else {
288 framing_params->sleep_time_ns = 14000000;
289 }
290 } else {
291 // Assume the sample rate is 44100
292 if (a2dp_aptx_encoder_cb.use_SCMS_T) {
293 framing_params->sleep_time_ns = 14000000;
294 } else {
295 framing_params->sleep_time_ns = 15000000;
296 }
297 }
298
299 LOG_INFO("%s: sleep_time_ns = %" PRIu64, __func__,
300 framing_params->sleep_time_ns);
301 }
302
303 //
304 // Set frame size and transmission interval needed to stream the required
305 // sample rate using 2-DH5 packets for aptX and 2-DH3 packets for aptX-LL.
306 // With SCMS-T enabled we need to reserve room for extra headers added later.
307 // Packets are always sent at equals time intervals but to achieve the
308 // required sample rate, the frame size needs to change on occasion.
309 //
310 // Also need to specify how many of the required PCM samples are read at a
311 // time:
312 // aptx_bytes = pcm_reads * pcm_bytes_per_read / 4
313 // and
314 // number of aptX samples produced = pcm_bytes_per_read / 16
315 //
aptx_update_framing_params(tAPTX_FRAMING_PARAMS * framing_params)316 static void aptx_update_framing_params(tAPTX_FRAMING_PARAMS* framing_params) {
317 if (a2dp_aptx_encoder_cb.feeding_params.sample_rate == 48000) {
318 if (a2dp_aptx_encoder_cb.use_SCMS_T) {
319 framing_params->aptx_bytes = 624;
320 framing_params->pcm_bytes_per_read = 208;
321 framing_params->pcm_reads = 12;
322 } else {
323 framing_params->aptx_bytes = 672;
324 framing_params->pcm_bytes_per_read = 224;
325 framing_params->pcm_reads = 12;
326 }
327 } else {
328 // Assume the sample rate is 44100
329 if (a2dp_aptx_encoder_cb.use_SCMS_T) {
330 if (++framing_params->frame_size_counter < 20) {
331 framing_params->aptx_bytes = 616;
332 framing_params->pcm_bytes_per_read = 224;
333 framing_params->pcm_reads = 11;
334 } else {
335 framing_params->aptx_bytes = 644;
336 framing_params->pcm_bytes_per_read = 368;
337 framing_params->pcm_reads = 7;
338 framing_params->frame_size_counter = 0;
339 }
340 } else {
341 if (++framing_params->frame_size_counter < 8) {
342 framing_params->aptx_bytes = 660;
343 framing_params->pcm_bytes_per_read = 240;
344 framing_params->pcm_reads = 11;
345 } else {
346 framing_params->aptx_bytes = 672;
347 framing_params->pcm_bytes_per_read = 224;
348 framing_params->pcm_reads = 12;
349 framing_params->frame_size_counter = 0;
350 }
351 }
352 }
353
354 LOG_VERBOSE("%s: sleep_time_ns = %" PRIu64
355 " aptx_bytes = %u "
356 "pcm_bytes_per_read = %u pcm_reads = %u frame_size_counter = %u",
357 __func__, framing_params->sleep_time_ns,
358 framing_params->aptx_bytes, framing_params->pcm_bytes_per_read,
359 framing_params->pcm_reads, framing_params->frame_size_counter);
360 }
361
a2dp_vendor_aptx_feeding_reset(void)362 void a2dp_vendor_aptx_feeding_reset(void) {
363 aptx_init_framing_params(&a2dp_aptx_encoder_cb.framing_params);
364 }
365
a2dp_vendor_aptx_feeding_flush(void)366 void a2dp_vendor_aptx_feeding_flush(void) {
367 aptx_init_framing_params(&a2dp_aptx_encoder_cb.framing_params);
368 }
369
a2dp_vendor_aptx_get_encoder_interval_ms(void)370 uint64_t a2dp_vendor_aptx_get_encoder_interval_ms(void) {
371 return a2dp_aptx_encoder_cb.framing_params.sleep_time_ns / (1000 * 1000);
372 }
373
a2dp_vendor_aptx_send_frames(uint64_t timestamp_us)374 void a2dp_vendor_aptx_send_frames(uint64_t timestamp_us) {
375 tAPTX_FRAMING_PARAMS* framing_params = &a2dp_aptx_encoder_cb.framing_params;
376
377 // Prepare the packet to send
378 BT_HDR* p_buf = (BT_HDR*)osi_malloc(BT_DEFAULT_BUFFER_SIZE);
379 p_buf->offset = A2DP_APTX_OFFSET;
380 p_buf->len = 0;
381 p_buf->layer_specific = 0;
382
383 uint8_t* encoded_ptr = (uint8_t*)(p_buf + 1);
384 encoded_ptr += p_buf->offset;
385
386 aptx_update_framing_params(framing_params);
387
388 //
389 // Read the PCM data and encode it
390 //
391 uint16_t read_buffer16[A2DP_APTX_MAX_PCM_BYTES_PER_READ / sizeof(uint16_t)];
392 uint32_t expected_read_bytes =
393 framing_params->pcm_reads * framing_params->pcm_bytes_per_read;
394 size_t encoded_ptr_index = 0;
395 size_t pcm_bytes_encoded = 0;
396 uint32_t bytes_read = 0;
397
398 a2dp_aptx_encoder_cb.stats.media_read_total_expected_packets++;
399 a2dp_aptx_encoder_cb.stats.media_read_total_expected_reads_count++;
400 a2dp_aptx_encoder_cb.stats.media_read_total_expected_read_bytes +=
401 expected_read_bytes;
402
403 LOG_VERBOSE("%s: PCM read of size %u", __func__, expected_read_bytes);
404 bytes_read = a2dp_aptx_encoder_cb.read_callback((uint8_t*)read_buffer16,
405 expected_read_bytes);
406 a2dp_aptx_encoder_cb.stats.media_read_total_actual_read_bytes += bytes_read;
407 if (bytes_read < expected_read_bytes) {
408 LOG_WARN("%s: underflow at PCM reading: read %u bytes instead of %u",
409 __func__, bytes_read, expected_read_bytes);
410 a2dp_aptx_encoder_cb.stats.media_read_total_dropped_packets++;
411 osi_free(p_buf);
412 return;
413 }
414 a2dp_aptx_encoder_cb.stats.media_read_total_actual_reads_count++;
415
416 for (uint32_t reads = 0, offset = 0; reads < framing_params->pcm_reads;
417 reads++, offset +=
418 (framing_params->pcm_bytes_per_read / sizeof(uint16_t))) {
419 pcm_bytes_encoded += aptx_encode_16bit(framing_params, &encoded_ptr_index,
420 read_buffer16 + offset, encoded_ptr);
421 }
422
423 // Compute the number of encoded bytes
424 const int COMPRESSION_RATIO = 4;
425 size_t encoded_bytes = pcm_bytes_encoded / COMPRESSION_RATIO;
426 p_buf->len += encoded_bytes;
427 LOG_VERBOSE("%s: encoded %zu PCM bytes to %zu", __func__, pcm_bytes_encoded,
428 encoded_bytes);
429
430 // Update the RTP timestamp
431 *((uint32_t*)(p_buf + 1)) = a2dp_aptx_encoder_cb.timestamp;
432 const uint8_t BYTES_PER_FRAME = 2;
433 uint32_t rtp_timestamp =
434 (pcm_bytes_encoded / a2dp_aptx_encoder_cb.feeding_params.channel_count) /
435 BYTES_PER_FRAME;
436 a2dp_aptx_encoder_cb.timestamp += rtp_timestamp;
437
438 if (p_buf->len > 0) {
439 a2dp_aptx_encoder_cb.enqueue_callback(p_buf, 1, bytes_read);
440 } else {
441 a2dp_aptx_encoder_cb.stats.media_read_total_dropped_packets++;
442 osi_free(p_buf);
443 }
444 }
445
aptx_encode_16bit(tAPTX_FRAMING_PARAMS * framing_params,size_t * data_out_index,uint16_t * data16_in,uint8_t * data_out)446 static size_t aptx_encode_16bit(tAPTX_FRAMING_PARAMS* framing_params,
447 size_t* data_out_index, uint16_t* data16_in,
448 uint8_t* data_out) {
449 size_t pcm_bytes_encoded = 0;
450 size_t frame = 0;
451
452 for (size_t aptx_samples = 0;
453 aptx_samples < framing_params->pcm_bytes_per_read / 16; aptx_samples++) {
454 uint32_t pcmL[4];
455 uint32_t pcmR[4];
456 uint16_t encoded_sample[2];
457
458 for (size_t i = 0, j = frame; i < 4; i++, j++) {
459 pcmL[i] = (uint16_t) * (data16_in + (2 * j));
460 pcmR[i] = (uint16_t) * (data16_in + ((2 * j) + 1));
461 }
462
463 aptx_encoder_encode_stereo_func(a2dp_aptx_encoder_cb.aptx_encoder_state,
464 &pcmL, &pcmR, &encoded_sample);
465
466 data_out[*data_out_index + 0] = (uint8_t)((encoded_sample[0] >> 8) & 0xff);
467 data_out[*data_out_index + 1] = (uint8_t)((encoded_sample[0] >> 0) & 0xff);
468 data_out[*data_out_index + 2] = (uint8_t)((encoded_sample[1] >> 8) & 0xff);
469 data_out[*data_out_index + 3] = (uint8_t)((encoded_sample[1] >> 0) & 0xff);
470
471 frame += 4;
472 pcm_bytes_encoded += 16;
473 *data_out_index += 4;
474 }
475
476 return pcm_bytes_encoded;
477 }
478
encoderIntervalMs() const479 uint64_t A2dpCodecConfigAptx::encoderIntervalMs() const {
480 return a2dp_vendor_aptx_get_encoder_interval_ms();
481 }
482
getEffectiveMtu() const483 int A2dpCodecConfigAptx::getEffectiveMtu() const {
484 return a2dp_aptx_encoder_cb.peer_mtu;
485 }
486
debug_codec_dump(int fd)487 void A2dpCodecConfigAptx::debug_codec_dump(int fd) {
488 a2dp_aptx_encoder_stats_t* stats = &a2dp_aptx_encoder_cb.stats;
489
490 A2dpCodecConfig::debug_codec_dump(fd);
491
492 dprintf(fd,
493 " Packet counts (expected/dropped) : %zu / "
494 "%zu\n",
495 stats->media_read_total_expected_packets,
496 stats->media_read_total_dropped_packets);
497
498 dprintf(fd,
499 " PCM read counts (expected/actual) : %zu / "
500 "%zu\n",
501 stats->media_read_total_expected_reads_count,
502 stats->media_read_total_actual_reads_count);
503
504 dprintf(fd,
505 " PCM read bytes (expected/actual) : %zu / "
506 "%zu\n",
507 stats->media_read_total_expected_read_bytes,
508 stats->media_read_total_actual_read_bytes);
509 }
510