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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_aac_encoder"
18 
19 #include "a2dp_aac_encoder.h"
20 
21 #include <inttypes.h>
22 #include <stdio.h>
23 #include <string.h>
24 
25 #include <aacenc_lib.h>
26 #include <base/logging.h>
27 
28 #include "a2dp_aac.h"
29 #include "bt_common.h"
30 #include "common/time_util.h"
31 #include "osi/include/log.h"
32 #include "osi/include/osi.h"
33 
34 //
35 // Encoder for AAC Source Codec
36 //
37 
38 // A2DP AAC encoder interval in milliseconds
39 #define A2DP_AAC_ENCODER_INTERVAL_MS 20
40 
41 // offset
42 #if (BTA_AV_CO_CP_SCMS_T == TRUE)
43 #define A2DP_AAC_OFFSET (AVDT_MEDIA_OFFSET + 1)
44 #else
45 #define A2DP_AAC_OFFSET AVDT_MEDIA_OFFSET
46 #endif
47 
48 typedef struct {
49   uint32_t sample_rate;
50   uint8_t channel_mode;
51   uint8_t bits_per_sample;
52   uint32_t frame_length;         // Samples per channel in a frame
53   uint8_t input_channels_n;      // Number of channels
54   int max_encoded_buffer_bytes;  // Max encoded bytes per frame
55 } tA2DP_AAC_ENCODER_PARAMS;
56 
57 typedef struct {
58   uint32_t counter;
59   uint32_t bytes_per_tick; /* pcm bytes read each media task tick */
60   uint64_t last_frame_us;
61 } tA2DP_AAC_FEEDING_STATE;
62 
63 typedef struct {
64   uint64_t session_start_us;
65 
66   size_t media_read_total_expected_packets;
67   size_t media_read_total_expected_reads_count;
68   size_t media_read_total_expected_read_bytes;
69 
70   size_t media_read_total_dropped_packets;
71   size_t media_read_total_actual_reads_count;
72   size_t media_read_total_actual_read_bytes;
73 } a2dp_aac_encoder_stats_t;
74 
75 typedef struct {
76   a2dp_source_read_callback_t read_callback;
77   a2dp_source_enqueue_callback_t enqueue_callback;
78   uint16_t TxAaMtuSize;
79 
80   bool use_SCMS_T;
81   bool is_peer_edr;          // True if the peer device supports EDR
82   bool peer_supports_3mbps;  // True if the peer device supports 3Mbps EDR
83   uint16_t peer_mtu;         // MTU of the A2DP peer
84   uint32_t timestamp;        // Timestamp for the A2DP frames
85 
86   HANDLE_AACENCODER aac_handle;
87   bool has_aac_handle;  // True if aac_handle is valid
88 
89   tA2DP_FEEDING_PARAMS feeding_params;
90   tA2DP_AAC_ENCODER_PARAMS aac_encoder_params;
91   tA2DP_AAC_FEEDING_STATE aac_feeding_state;
92 
93   a2dp_aac_encoder_stats_t stats;
94 } tA2DP_AAC_ENCODER_CB;
95 
96 static tA2DP_AAC_ENCODER_CB a2dp_aac_encoder_cb;
97 
98 static void a2dp_aac_encoder_update(uint16_t peer_mtu,
99                                     A2dpCodecConfig* a2dp_codec_config,
100                                     bool* p_restart_input,
101                                     bool* p_restart_output,
102                                     bool* p_config_updated);
103 static void a2dp_aac_get_num_frame_iteration(uint8_t* num_of_iterations,
104                                              uint8_t* num_of_frames,
105                                              uint64_t timestamp_us);
106 static void a2dp_aac_encode_frames(uint8_t nb_frame);
107 static bool a2dp_aac_read_feeding(uint8_t* read_buffer, uint32_t* bytes_read);
108 
A2DP_LoadEncoderAac(void)109 bool A2DP_LoadEncoderAac(void) {
110   // Nothing to do - the library is statically linked
111   return true;
112 }
113 
A2DP_UnloadEncoderAac(void)114 void A2DP_UnloadEncoderAac(void) {
115   // Nothing to do - the library is statically linked
116   if (a2dp_aac_encoder_cb.has_aac_handle)
117     aacEncClose(&a2dp_aac_encoder_cb.aac_handle);
118   memset(&a2dp_aac_encoder_cb, 0, sizeof(a2dp_aac_encoder_cb));
119 }
120 
a2dp_aac_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)121 void a2dp_aac_encoder_init(const tA2DP_ENCODER_INIT_PEER_PARAMS* p_peer_params,
122                            A2dpCodecConfig* a2dp_codec_config,
123                            a2dp_source_read_callback_t read_callback,
124                            a2dp_source_enqueue_callback_t enqueue_callback) {
125   if (a2dp_aac_encoder_cb.has_aac_handle)
126     aacEncClose(&a2dp_aac_encoder_cb.aac_handle);
127   memset(&a2dp_aac_encoder_cb, 0, sizeof(a2dp_aac_encoder_cb));
128 
129   a2dp_aac_encoder_cb.stats.session_start_us =
130       bluetooth::common::time_get_os_boottime_us();
131 
132   a2dp_aac_encoder_cb.read_callback = read_callback;
133   a2dp_aac_encoder_cb.enqueue_callback = enqueue_callback;
134   a2dp_aac_encoder_cb.is_peer_edr = p_peer_params->is_peer_edr;
135   a2dp_aac_encoder_cb.peer_supports_3mbps = p_peer_params->peer_supports_3mbps;
136   a2dp_aac_encoder_cb.peer_mtu = p_peer_params->peer_mtu;
137   a2dp_aac_encoder_cb.timestamp = 0;
138 
139   a2dp_aac_encoder_cb.use_SCMS_T = false;  // TODO: should be a parameter
140 #if (BTA_AV_CO_CP_SCMS_T == TRUE)
141   a2dp_aac_encoder_cb.use_SCMS_T = true;
142 #endif
143 
144   // NOTE: Ignore the restart_input / restart_output flags - this initization
145   // happens when the connection is (re)started.
146   bool restart_input = false;
147   bool restart_output = false;
148   bool config_updated = false;
149   a2dp_aac_encoder_update(a2dp_aac_encoder_cb.peer_mtu, a2dp_codec_config,
150                           &restart_input, &restart_output, &config_updated);
151 }
152 
updateEncoderUserConfig(const tA2DP_ENCODER_INIT_PEER_PARAMS * p_peer_params,bool * p_restart_input,bool * p_restart_output,bool * p_config_updated)153 bool A2dpCodecConfigAacSource::updateEncoderUserConfig(
154     const tA2DP_ENCODER_INIT_PEER_PARAMS* p_peer_params, bool* p_restart_input,
155     bool* p_restart_output, bool* p_config_updated) {
156   a2dp_aac_encoder_cb.is_peer_edr = p_peer_params->is_peer_edr;
157   a2dp_aac_encoder_cb.peer_supports_3mbps = p_peer_params->peer_supports_3mbps;
158   a2dp_aac_encoder_cb.peer_mtu = p_peer_params->peer_mtu;
159   a2dp_aac_encoder_cb.timestamp = 0;
160 
161   if (a2dp_aac_encoder_cb.peer_mtu == 0) {
162     LOG_ERROR(LOG_TAG,
163               "%s: Cannot update the codec encoder for %s: "
164               "invalid peer MTU",
165               __func__, name().c_str());
166     return false;
167   }
168 
169   a2dp_aac_encoder_update(a2dp_aac_encoder_cb.peer_mtu, this, p_restart_input,
170                           p_restart_output, p_config_updated);
171   return true;
172 }
173 
174 // Update the A2DP AAC encoder.
175 // |peer_mtu| is the peer MTU.
176 // |a2dp_codec_config| is the A2DP codec to use for the update.
a2dp_aac_encoder_update(uint16_t peer_mtu,A2dpCodecConfig * a2dp_codec_config,bool * p_restart_input,bool * p_restart_output,bool * p_config_updated)177 static void a2dp_aac_encoder_update(uint16_t peer_mtu,
178                                     A2dpCodecConfig* a2dp_codec_config,
179                                     bool* p_restart_input,
180                                     bool* p_restart_output,
181                                     bool* p_config_updated) {
182   tA2DP_AAC_ENCODER_PARAMS* p_encoder_params =
183       &a2dp_aac_encoder_cb.aac_encoder_params;
184   uint8_t codec_info[AVDT_CODEC_SIZE];
185   AACENC_ERROR aac_error;
186   int aac_param_value, aac_sampling_freq, aac_peak_bit_rate;
187 
188   *p_restart_input = false;
189   *p_restart_output = false;
190   *p_config_updated = false;
191 
192   if (!a2dp_aac_encoder_cb.has_aac_handle) {
193     AACENC_ERROR aac_error = aacEncOpen(&a2dp_aac_encoder_cb.aac_handle, 0,
194                                         2 /* max 2 channels: stereo */);
195     if (aac_error != AACENC_OK) {
196       LOG_ERROR(LOG_TAG, "%s: Cannot open AAC encoder handle: AAC error 0x%x",
197                 __func__, aac_error);
198       return;  // TODO: Return an error?
199     }
200     a2dp_aac_encoder_cb.has_aac_handle = true;
201   }
202 
203   if (!a2dp_codec_config->copyOutOtaCodecConfig(codec_info)) {
204     LOG_ERROR(LOG_TAG,
205               "%s: Cannot update the codec encoder for %s: "
206               "invalid codec config",
207               __func__, a2dp_codec_config->name().c_str());
208     return;
209   }
210   const uint8_t* p_codec_info = codec_info;
211 
212   // The feeding parameters
213   tA2DP_FEEDING_PARAMS* p_feeding_params = &a2dp_aac_encoder_cb.feeding_params;
214   p_feeding_params->sample_rate = A2DP_GetTrackSampleRateAac(p_codec_info);
215   p_feeding_params->bits_per_sample =
216       a2dp_codec_config->getAudioBitsPerSample();
217   p_feeding_params->channel_count = A2DP_GetTrackChannelCountAac(p_codec_info);
218   LOG_DEBUG(LOG_TAG, "%s: sample_rate=%u bits_per_sample=%u channel_count=%u",
219             __func__, p_feeding_params->sample_rate,
220             p_feeding_params->bits_per_sample, p_feeding_params->channel_count);
221   a2dp_aac_feeding_reset();
222 
223   // The codec parameters
224   p_encoder_params->sample_rate =
225       a2dp_aac_encoder_cb.feeding_params.sample_rate;
226   p_encoder_params->channel_mode = A2DP_GetChannelModeCodeAac(p_codec_info);
227 
228   LOG_VERBOSE(LOG_TAG, "%s: original AVDTP MTU size: %d", __func__,
229               a2dp_aac_encoder_cb.TxAaMtuSize);
230   if (a2dp_aac_encoder_cb.is_peer_edr &&
231       !a2dp_aac_encoder_cb.peer_supports_3mbps) {
232     // This condition would be satisfied only if the remote device is
233     // EDR and supports only 2 Mbps, but the effective AVDTP MTU size
234     // exceeds the 2DH5 packet size.
235     LOG_VERBOSE(LOG_TAG,
236                 "%s: The remote device is EDR but does not support 3 Mbps",
237                 __func__);
238     if (peer_mtu > MAX_2MBPS_AVDTP_MTU) {
239       LOG_WARN(LOG_TAG, "%s: Restricting AVDTP MTU size from %d to %d",
240                __func__, peer_mtu, MAX_2MBPS_AVDTP_MTU);
241       peer_mtu = MAX_2MBPS_AVDTP_MTU;
242     }
243   }
244   uint16_t mtu_size = BT_DEFAULT_BUFFER_SIZE - A2DP_AAC_OFFSET - sizeof(BT_HDR);
245   if (mtu_size < peer_mtu) {
246     a2dp_aac_encoder_cb.TxAaMtuSize = mtu_size;
247   } else {
248     a2dp_aac_encoder_cb.TxAaMtuSize = peer_mtu;
249   }
250 
251   LOG_DEBUG(LOG_TAG, "%s: MTU=%d, peer_mtu=%d", __func__,
252             a2dp_aac_encoder_cb.TxAaMtuSize, peer_mtu);
253   LOG_DEBUG(LOG_TAG, "%s: sample_rate: %d channel_mode: %d ", __func__,
254             p_encoder_params->sample_rate, p_encoder_params->channel_mode);
255 
256   // Set the encoder's parameters: Audio Object Type - MANDATORY
257   // A2DP_AAC_OBJECT_TYPE_MPEG2_LC -> AOT_AAC_LC
258   // A2DP_AAC_OBJECT_TYPE_MPEG4_LC -> AOT_AAC_LC
259   // A2DP_AAC_OBJECT_TYPE_MPEG4_LTP -> AOT_AAC_LTP
260   // A2DP_AAC_OBJECT_TYPE_MPEG4_SCALABLE -> AOT_AAC_SCAL
261   aac_param_value = AOT_AAC_LC;
262   int object_type = A2DP_GetObjectTypeCodeAac(p_codec_info);
263   switch (object_type) {
264     case A2DP_AAC_OBJECT_TYPE_MPEG2_LC:
265       aac_param_value = AOT_AAC_LC;
266       break;
267     case A2DP_AAC_OBJECT_TYPE_MPEG4_LC:
268       aac_param_value = AOT_AAC_LC;
269       break;
270     case A2DP_AAC_OBJECT_TYPE_MPEG4_LTP:
271       aac_param_value = AOT_AAC_LTP;
272       break;
273     case A2DP_AAC_OBJECT_TYPE_MPEG4_SCALABLE:
274       aac_param_value = AOT_AAC_SCAL;
275       break;
276     default:
277       LOG_ERROR(LOG_TAG,
278                 "%s: Cannot set AAC parameter AACENC_AOT: "
279                 "invalid object type %d",
280                 __func__, object_type);
281       return;  // TODO: Return an error?
282   }
283   aac_error = aacEncoder_SetParam(a2dp_aac_encoder_cb.aac_handle, AACENC_AOT,
284                                   aac_param_value);
285   if (aac_error != AACENC_OK) {
286     LOG_ERROR(LOG_TAG,
287               "%s: Cannot set AAC parameter AACENC_AOT to %d: "
288               "AAC error 0x%x",
289               __func__, aac_param_value, aac_error);
290     return;  // TODO: Return an error?
291   }
292 
293   // Set the encoder's parameters: audioMuxVersion
294   aac_param_value = 2;  // audioMuxVersion = "2"
295   aac_error = aacEncoder_SetParam(a2dp_aac_encoder_cb.aac_handle,
296                                   AACENC_AUDIOMUXVER, aac_param_value);
297   if (aac_error != AACENC_OK) {
298     LOG_ERROR(LOG_TAG,
299               "%s: Cannot set AAC parameter AACENC_AUDIOMUXVER to %d: "
300               "AAC error 0x%x",
301               __func__, aac_param_value, aac_error);
302     return;  // TODO: Return an error?
303   }
304 
305   // Set the encoder's parameters: Signaling mode of the extension AOT
306   aac_param_value = 1;  // Signaling mode of the extension AOT = 1
307   aac_error = aacEncoder_SetParam(a2dp_aac_encoder_cb.aac_handle,
308                                   AACENC_SIGNALING_MODE, aac_param_value);
309   if (aac_error != AACENC_OK) {
310     LOG_ERROR(LOG_TAG,
311               "%s: Cannot set AAC parameter AACENC_SIGNALING_MODE to %d: "
312               "AAC error 0x%x",
313               __func__, aac_param_value, aac_error);
314     return;  // TODO: Return an error?
315   }
316 
317   // Set the encoder's parameters: Sample Rate - MANDATORY
318   aac_param_value = A2DP_GetTrackSampleRateAac(p_codec_info);
319   aac_error = aacEncoder_SetParam(a2dp_aac_encoder_cb.aac_handle,
320                                   AACENC_SAMPLERATE, aac_param_value);
321   if (aac_error != AACENC_OK) {
322     LOG_ERROR(LOG_TAG,
323               "%s: Cannot set AAC parameter AACENC_SAMPLERATE to %d: "
324               "AAC error 0x%x",
325               __func__, aac_param_value, aac_error);
326     return;  // TODO: Return an error?
327   }
328   aac_sampling_freq = aac_param_value;  // Save for extra usage below
329 
330   // Set the encoder's parameters: Bit Rate - MANDATORY
331   aac_param_value = A2DP_GetBitRateAac(p_codec_info);
332   // Calculate the bit rate from MTU and sampling frequency
333   aac_peak_bit_rate =
334       A2DP_ComputeMaxBitRateAac(p_codec_info, a2dp_aac_encoder_cb.TxAaMtuSize);
335   aac_param_value = std::min(aac_param_value, aac_peak_bit_rate);
336   LOG_DEBUG(LOG_TAG, "%s: MTU = %d Sampling Frequency = %d Bit Rate = %d",
337             __func__, a2dp_aac_encoder_cb.TxAaMtuSize, aac_sampling_freq,
338             aac_param_value);
339   if (aac_param_value == -1) {
340     LOG_ERROR(LOG_TAG,
341               "%s: Cannot set AAC parameter AACENC_BITRATE: "
342               "invalid codec bit rate",
343               __func__);
344     return;  // TODO: Return an error?
345   }
346   aac_error = aacEncoder_SetParam(a2dp_aac_encoder_cb.aac_handle,
347                                   AACENC_BITRATE, aac_param_value);
348   if (aac_error != AACENC_OK) {
349     LOG_ERROR(LOG_TAG,
350               "%s: Cannot set AAC parameter AACENC_BITRATE to %d: "
351               "AAC error 0x%x",
352               __func__, aac_param_value, aac_error);
353     return;  // TODO: Return an error?
354   }
355 
356   // Set the encoder's parameters: PEAK Bit Rate
357   aac_error = aacEncoder_SetParam(a2dp_aac_encoder_cb.aac_handle,
358                                   AACENC_PEAK_BITRATE, aac_peak_bit_rate);
359   if (aac_error != AACENC_OK) {
360     LOG_ERROR(LOG_TAG,
361               "%s: Cannot set AAC parameter AACENC_PEAK_BITRATE to %d: "
362               "AAC error 0x%x",
363               __func__, aac_peak_bit_rate, aac_error);
364     return;  // TODO: Return an error?
365   }
366 
367   // Set the encoder's parameters: Channel Mode - MANDATORY
368   if (A2DP_GetTrackChannelCountAac(p_codec_info) == 1) {
369     aac_param_value = MODE_1;  // Mono
370   } else {
371     aac_param_value = MODE_2;  // Stereo
372   }
373   aac_error = aacEncoder_SetParam(a2dp_aac_encoder_cb.aac_handle,
374                                   AACENC_CHANNELMODE, aac_param_value);
375   if (aac_error != AACENC_OK) {
376     LOG_ERROR(LOG_TAG,
377               "%s: Cannot set AAC parameter AACENC_CHANNELMODE to %d: "
378               "AAC error 0x%x",
379               __func__, aac_param_value, aac_error);
380     return;  // TODO: Return an error?
381   }
382 
383   // Set the encoder's parameters: Transport Type
384   aac_param_value = TT_MP4_LATM_MCP1;  // muxConfigPresent = 1
385   aac_error = aacEncoder_SetParam(a2dp_aac_encoder_cb.aac_handle,
386                                   AACENC_TRANSMUX, aac_param_value);
387   if (aac_error != AACENC_OK) {
388     LOG_ERROR(LOG_TAG,
389               "%s: Cannot set AAC parameter AACENC_TRANSMUX to %d: "
390               "AAC error 0x%x",
391               __func__, aac_param_value, aac_error);
392     return;  // TODO: Return an error?
393   }
394 
395   // Set the encoder's parameters: Header Period
396   aac_param_value = 1;
397   aac_error = aacEncoder_SetParam(a2dp_aac_encoder_cb.aac_handle,
398                                   AACENC_HEADER_PERIOD, aac_param_value);
399   if (aac_error != AACENC_OK) {
400     LOG_ERROR(LOG_TAG,
401               "%s: Cannot set AAC parameter AACENC_HEADER_PERIOD to %d: "
402               "AAC error 0x%x",
403               __func__, aac_param_value, aac_error);
404     return;  // TODO: Return an error?
405   }
406 
407   // Set the encoder's parameters: Variable Bit Rate Support
408   aac_param_value = A2DP_GetVariableBitRateSupportAac(p_codec_info);
409   if (aac_param_value == -1) {
410     LOG_ERROR(LOG_TAG,
411               "%s: Cannot set AAC parameter AACENC_BITRATEMODE: "
412               "invalid codec bit rate mode",
413               __func__);
414     return;  // TODO: Return an error?
415   }
416   aac_error = aacEncoder_SetParam(a2dp_aac_encoder_cb.aac_handle,
417                                   AACENC_BITRATEMODE, aac_param_value);
418   if (aac_error != AACENC_OK) {
419     LOG_ERROR(LOG_TAG,
420               "%s: Cannot set AAC parameter AACENC_BITRATEMODE to %d: "
421               "AAC error 0x%x",
422               __func__, aac_param_value, aac_error);
423     return;  // TODO: Return an error?
424   }
425 
426   // Mark the end of setting the encoder's parameters
427   aac_error =
428       aacEncEncode(a2dp_aac_encoder_cb.aac_handle, NULL, NULL, NULL, NULL);
429   if (aac_error != AACENC_OK) {
430     LOG_ERROR(LOG_TAG,
431               "%s: Cannot complete setting the AAC parameters: AAC error 0x%x",
432               __func__, aac_error);
433     return;  // TODO: Return an error?
434   }
435 
436   // Retrieve the encoder info so we can save the frame length
437   AACENC_InfoStruct aac_info;
438   aac_error = aacEncInfo(a2dp_aac_encoder_cb.aac_handle, &aac_info);
439   if (aac_error != AACENC_OK) {
440     LOG_ERROR(LOG_TAG,
441               "%s: Cannot retrieve the AAC encoder info: AAC error 0x%x",
442               __func__, aac_error);
443     return;  // TODO: Return an error?
444   }
445   p_encoder_params->frame_length = aac_info.frameLength;
446   p_encoder_params->input_channels_n = aac_info.inputChannels;
447   p_encoder_params->max_encoded_buffer_bytes = aac_info.maxOutBufBytes;
448   LOG_DEBUG(LOG_TAG,
449             "%s: AAC frame_length = %u input_channels_n = %u "
450             "max_encoded_buffer_bytes = %d",
451             __func__, p_encoder_params->frame_length,
452             p_encoder_params->input_channels_n,
453             p_encoder_params->max_encoded_buffer_bytes);
454 }
455 
a2dp_aac_encoder_cleanup(void)456 void a2dp_aac_encoder_cleanup(void) {
457   if (a2dp_aac_encoder_cb.has_aac_handle)
458     aacEncClose(&a2dp_aac_encoder_cb.aac_handle);
459   memset(&a2dp_aac_encoder_cb, 0, sizeof(a2dp_aac_encoder_cb));
460 }
461 
a2dp_aac_feeding_reset(void)462 void a2dp_aac_feeding_reset(void) {
463   /* By default, just clear the entire state */
464   memset(&a2dp_aac_encoder_cb.aac_feeding_state, 0,
465          sizeof(a2dp_aac_encoder_cb.aac_feeding_state));
466 
467   a2dp_aac_encoder_cb.aac_feeding_state.bytes_per_tick =
468       (a2dp_aac_encoder_cb.feeding_params.sample_rate *
469        a2dp_aac_encoder_cb.feeding_params.bits_per_sample / 8 *
470        a2dp_aac_encoder_cb.feeding_params.channel_count *
471        A2DP_AAC_ENCODER_INTERVAL_MS) /
472       1000;
473 
474   LOG_DEBUG(LOG_TAG, "%s: PCM bytes per tick %u", __func__,
475             a2dp_aac_encoder_cb.aac_feeding_state.bytes_per_tick);
476 }
477 
a2dp_aac_feeding_flush(void)478 void a2dp_aac_feeding_flush(void) {
479   a2dp_aac_encoder_cb.aac_feeding_state.counter = 0;
480 }
481 
a2dp_aac_get_encoder_interval_ms(void)482 uint64_t a2dp_aac_get_encoder_interval_ms(void) {
483   return A2DP_AAC_ENCODER_INTERVAL_MS;
484 }
485 
a2dp_aac_send_frames(uint64_t timestamp_us)486 void a2dp_aac_send_frames(uint64_t timestamp_us) {
487   uint8_t nb_frame = 0;
488   uint8_t nb_iterations = 0;
489 
490   a2dp_aac_get_num_frame_iteration(&nb_iterations, &nb_frame, timestamp_us);
491   LOG_VERBOSE(LOG_TAG, "%s: Sending %d frames per iteration, %d iterations",
492               __func__, nb_frame, nb_iterations);
493   if (nb_frame == 0) return;
494 
495   for (uint8_t counter = 0; counter < nb_iterations; counter++) {
496     // Transcode frame and enqueue
497     a2dp_aac_encode_frames(nb_frame);
498   }
499 }
500 
501 // Obtains the number of frames to send and number of iterations
502 // to be used. |num_of_iterations| and |num_of_frames| parameters
503 // are used as output param for returning the respective values.
a2dp_aac_get_num_frame_iteration(uint8_t * num_of_iterations,uint8_t * num_of_frames,uint64_t timestamp_us)504 static void a2dp_aac_get_num_frame_iteration(uint8_t* num_of_iterations,
505                                              uint8_t* num_of_frames,
506                                              uint64_t timestamp_us) {
507   uint32_t result = 0;
508   uint8_t nof = 0;
509   uint8_t noi = 1;
510 
511   uint32_t pcm_bytes_per_frame =
512       a2dp_aac_encoder_cb.aac_encoder_params.frame_length *
513       a2dp_aac_encoder_cb.feeding_params.channel_count *
514       a2dp_aac_encoder_cb.feeding_params.bits_per_sample / 8;
515   LOG_VERBOSE(LOG_TAG, "%s: pcm_bytes_per_frame %u", __func__,
516               pcm_bytes_per_frame);
517 
518   uint32_t us_this_tick = A2DP_AAC_ENCODER_INTERVAL_MS * 1000;
519   uint64_t now_us = timestamp_us;
520   if (a2dp_aac_encoder_cb.aac_feeding_state.last_frame_us != 0)
521     us_this_tick =
522         (now_us - a2dp_aac_encoder_cb.aac_feeding_state.last_frame_us);
523   a2dp_aac_encoder_cb.aac_feeding_state.last_frame_us = now_us;
524 
525   a2dp_aac_encoder_cb.aac_feeding_state.counter +=
526       a2dp_aac_encoder_cb.aac_feeding_state.bytes_per_tick * us_this_tick /
527       (A2DP_AAC_ENCODER_INTERVAL_MS * 1000);
528 
529   result = a2dp_aac_encoder_cb.aac_feeding_state.counter / pcm_bytes_per_frame;
530   a2dp_aac_encoder_cb.aac_feeding_state.counter -= result * pcm_bytes_per_frame;
531   nof = result;
532 
533   LOG_VERBOSE(LOG_TAG, "%s: effective num of frames %u, iterations %u",
534               __func__, nof, noi);
535 
536   *num_of_frames = nof;
537   *num_of_iterations = noi;
538 }
539 
a2dp_aac_encode_frames(uint8_t nb_frame)540 static void a2dp_aac_encode_frames(uint8_t nb_frame) {
541   tA2DP_AAC_ENCODER_PARAMS* p_encoder_params =
542       &a2dp_aac_encoder_cb.aac_encoder_params;
543   tA2DP_FEEDING_PARAMS* p_feeding_params = &a2dp_aac_encoder_cb.feeding_params;
544   uint8_t remain_nb_frame = nb_frame;
545   uint8_t read_buffer[BT_DEFAULT_BUFFER_SIZE];
546   int pcm_bytes_per_frame = p_encoder_params->frame_length *
547                             p_feeding_params->channel_count *
548                             p_feeding_params->bits_per_sample / 8;
549   CHECK(pcm_bytes_per_frame <= static_cast<int>(sizeof(read_buffer)));
550 
551   // Setup the input buffer
552   AACENC_BufDesc in_buf_desc;
553   void* in_buf_vector[1] = {nullptr};
554   int in_buf_identifiers[1] = {IN_AUDIO_DATA};
555   int in_buf_sizes[1] = {pcm_bytes_per_frame};
556   int in_buf_element_sizes[1] = {p_feeding_params->bits_per_sample / 8};
557   in_buf_desc.numBufs = 1;
558   in_buf_desc.bufs = in_buf_vector;
559   in_buf_desc.bufferIdentifiers = in_buf_identifiers;
560   in_buf_desc.bufSizes = in_buf_sizes;
561   in_buf_desc.bufElSizes = in_buf_element_sizes;
562 
563   // Setup the output buffer (partially)
564   AACENC_BufDesc out_buf_desc;
565   void* out_buf_vector[1] = {nullptr};
566   int out_buf_identifiers[1] = {OUT_BITSTREAM_DATA};
567   int out_buf_sizes[1] = {p_encoder_params->max_encoded_buffer_bytes};
568   // NOTE: out_buf_element_sizes below is probably unused by the encoder
569   int out_buf_element_sizes[1] = {p_feeding_params->bits_per_sample / 8};
570   out_buf_desc.numBufs = 1;
571   out_buf_desc.bufs = out_buf_vector;
572   out_buf_desc.bufferIdentifiers = out_buf_identifiers;
573   out_buf_desc.bufSizes = out_buf_sizes;
574   out_buf_desc.bufElSizes = out_buf_element_sizes;
575   CHECK(p_encoder_params->max_encoded_buffer_bytes <=
576         static_cast<int>(BT_DEFAULT_BUFFER_SIZE - sizeof(BT_HDR)));
577 
578   AACENC_InArgs aac_in_args;
579   aac_in_args.numInSamples =
580       p_encoder_params->frame_length * p_feeding_params->channel_count;
581   aac_in_args.numAncBytes = 0;
582 
583   AACENC_OutArgs aac_out_args = {
584       .numOutBytes = 0, .numInSamples = 0, .numAncBytes = 0};
585 
586   uint32_t count;
587   uint32_t total_bytes_read = 0;
588   int written = 0;
589 
590   while (nb_frame) {
591     BT_HDR* p_buf = (BT_HDR*)osi_malloc(BT_DEFAULT_BUFFER_SIZE);
592     p_buf->offset = A2DP_AAC_OFFSET;
593     p_buf->len = 0;
594     p_buf->layer_specific = 0;
595     a2dp_aac_encoder_cb.stats.media_read_total_expected_packets++;
596 
597     count = 0;
598     do {
599       //
600       // Read the PCM data and encode it
601       //
602       uint32_t bytes_read = 0;
603       if (a2dp_aac_read_feeding(read_buffer, &bytes_read)) {
604         uint8_t* packet = (uint8_t*)(p_buf + 1) + p_buf->offset + p_buf->len;
605         if (!a2dp_aac_encoder_cb.has_aac_handle) {
606           LOG_ERROR(LOG_TAG, "%s: invalid AAC handle", __func__);
607           a2dp_aac_encoder_cb.stats.media_read_total_dropped_packets++;
608           osi_free(p_buf);
609           return;
610         }
611         in_buf_vector[0] = read_buffer;
612         out_buf_vector[0] = packet + count;
613         AACENC_ERROR aac_error =
614             aacEncEncode(a2dp_aac_encoder_cb.aac_handle, &in_buf_desc,
615                          &out_buf_desc, &aac_in_args, &aac_out_args);
616         if (aac_error != AACENC_OK) {
617           LOG_ERROR(LOG_TAG, "%s: AAC encoding error: 0x%x", __func__,
618                     aac_error);
619           a2dp_aac_encoder_cb.stats.media_read_total_dropped_packets++;
620           osi_free(p_buf);
621           return;
622         }
623         written = aac_out_args.numOutBytes;
624         count += written;
625         p_buf->len += written;
626         nb_frame--;
627         p_buf->layer_specific++;  // added a frame to the buffer
628       } else {
629         LOG_WARN(LOG_TAG, "%s: underflow %d", __func__, nb_frame);
630         a2dp_aac_encoder_cb.aac_feeding_state.counter +=
631             nb_frame * p_encoder_params->frame_length *
632             p_feeding_params->channel_count *
633             p_feeding_params->bits_per_sample / 8;
634 
635         // no more pcm to read
636         nb_frame = 0;
637       }
638       total_bytes_read += bytes_read;
639     } while ((written == 0) && nb_frame);
640 
641     // NOTE: We don't check whether the packet will fit in the MTU,
642     // because AAC doesn't give us control over the encoded frame size.
643     // If the packet is larger than the MTU, it will be fragmented before
644     // transmission.
645     if (p_buf->len) {
646       /*
647        * Timestamp of the media packet header represent the TS of the
648        * first frame, i.e the timestamp before including this frame.
649        */
650       *((uint32_t*)(p_buf + 1)) = a2dp_aac_encoder_cb.timestamp;
651 
652       a2dp_aac_encoder_cb.timestamp +=
653           p_buf->layer_specific * p_encoder_params->frame_length;
654 
655       uint8_t done_nb_frame = remain_nb_frame - nb_frame;
656       remain_nb_frame = nb_frame;
657       if (!a2dp_aac_encoder_cb.enqueue_callback(p_buf, done_nb_frame,
658                                                 total_bytes_read))
659         return;
660     } else {
661       a2dp_aac_encoder_cb.stats.media_read_total_dropped_packets++;
662       osi_free(p_buf);
663     }
664   }
665 }
666 
a2dp_aac_read_feeding(uint8_t * read_buffer,uint32_t * bytes_read)667 static bool a2dp_aac_read_feeding(uint8_t* read_buffer, uint32_t* bytes_read) {
668   uint32_t read_size = a2dp_aac_encoder_cb.aac_encoder_params.frame_length *
669                        a2dp_aac_encoder_cb.feeding_params.channel_count *
670                        a2dp_aac_encoder_cb.feeding_params.bits_per_sample / 8;
671 
672   a2dp_aac_encoder_cb.stats.media_read_total_expected_reads_count++;
673   a2dp_aac_encoder_cb.stats.media_read_total_expected_read_bytes += read_size;
674 
675   /* Read Data from UIPC channel */
676   uint32_t nb_byte_read =
677       a2dp_aac_encoder_cb.read_callback(read_buffer, read_size);
678   a2dp_aac_encoder_cb.stats.media_read_total_actual_read_bytes += nb_byte_read;
679   *bytes_read = nb_byte_read;
680 
681   if (nb_byte_read < read_size) {
682     if (nb_byte_read == 0) return false;
683 
684     /* Fill the unfilled part of the read buffer with silence (0) */
685     memset(((uint8_t*)read_buffer) + nb_byte_read, 0, read_size - nb_byte_read);
686     nb_byte_read = read_size;
687   }
688   a2dp_aac_encoder_cb.stats.media_read_total_actual_reads_count++;
689 
690   return true;
691 }
692 
encoderIntervalMs() const693 uint64_t A2dpCodecConfigAacSource::encoderIntervalMs() const {
694   return a2dp_aac_get_encoder_interval_ms();
695 }
696 
getEffectiveMtu() const697 int A2dpCodecConfigAacSource::getEffectiveMtu() const {
698   return a2dp_aac_encoder_cb.TxAaMtuSize;
699 }
700 
debug_codec_dump(int fd)701 void A2dpCodecConfigAacSource::debug_codec_dump(int fd) {
702   a2dp_aac_encoder_stats_t* stats = &a2dp_aac_encoder_cb.stats;
703 
704   A2dpCodecConfig::debug_codec_dump(fd);
705 
706   dprintf(fd,
707           "  Packet counts (expected/dropped)                        : %zu / "
708           "%zu\n",
709           stats->media_read_total_expected_packets,
710           stats->media_read_total_dropped_packets);
711 
712   dprintf(fd,
713           "  PCM read counts (expected/actual)                       : %zu / "
714           "%zu\n",
715           stats->media_read_total_expected_reads_count,
716           stats->media_read_total_actual_reads_count);
717 
718   dprintf(fd,
719           "  PCM read bytes (expected/actual)                        : %zu / "
720           "%zu\n",
721           stats->media_read_total_expected_read_bytes,
722           stats->media_read_total_actual_read_bytes);
723 }
724