xref: /btstack/src/classic/a2dp_source.c (revision d0c510fc6d1993c588c06d8e016d6e3f8412942f)
1 
2 /*
3  * Copyright (C) 2016 BlueKitchen GmbH
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the copyright holders nor the names of
15  *    contributors may be used to endorse or promote products derived
16  *    from this software without specific prior written permission.
17  * 4. Any redistribution, use, or modification is done solely for
18  *    personal benefit and not for any commercial purpose or for
19  *    monetary gain.
20  *
21  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
25  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
28  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
31  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * Please inquire about commercial licensing options at
35  * [email protected]
36  *
37  */
38 
39 #define __BTSTACK_FILE__ "a2dp_source.c"
40 
41 #include <stdint.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 #include "btstack.h"
47 #include "classic/avdtp.h"
48 #include "classic/avdtp_util.h"
49 #include "classic/avdtp_source.h"
50 #include "classic/a2dp_source.h"
51 
52 #define AVDTP_MAX_SEP_NUM 10
53 #define AVDTP_MEDIA_PAYLOAD_HEADER_SIZE 12
54 
55 static const char * default_a2dp_source_service_name = "BTstack A2DP Source Service";
56 static const char * default_a2dp_source_service_provider_name = "BTstack A2DP Source Service Provider";
57 static avdtp_context_t a2dp_source_context;
58 
59 static a2dp_state_t app_state = A2DP_IDLE;
60 static avdtp_stream_endpoint_context_t sc;
61 static avdtp_sep_t remote_seps[AVDTP_MAX_SEP_NUM];
62 static int remote_seps_index = 0;
63 
64 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
65 
66 void a2dp_source_create_sdp_record(uint8_t * service, uint32_t service_record_handle, uint16_t supported_features, const char * service_name, const char * service_provider_name){
67     uint8_t* attribute;
68     de_create_sequence(service);
69 
70     // 0x0000 "Service Record Handle"
71     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
72     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
73 
74     // 0x0001 "Service Class ID List"
75     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
76     attribute = de_push_sequence(service);
77     {
78         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AUDIO_SOURCE);
79     }
80     de_pop_sequence(service, attribute);
81 
82     // 0x0004 "Protocol Descriptor List"
83     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
84     attribute = de_push_sequence(service);
85     {
86         uint8_t* l2cpProtocol = de_push_sequence(attribute);
87         {
88             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
89             de_add_number(l2cpProtocol,  DE_UINT, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVDTP);
90         }
91         de_pop_sequence(attribute, l2cpProtocol);
92 
93         uint8_t* avProtocol = de_push_sequence(attribute);
94         {
95             de_add_number(avProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVDTP);  // avProtocol_service
96             de_add_number(avProtocol,  DE_UINT, DE_SIZE_16,  0x0103);  // version
97         }
98         de_pop_sequence(attribute, avProtocol);
99     }
100     de_pop_sequence(service, attribute);
101 
102     // 0x0005 "Public Browse Group"
103     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
104     attribute = de_push_sequence(service);
105     {
106         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
107     }
108     de_pop_sequence(service, attribute);
109 
110     // 0x0009 "Bluetooth Profile Descriptor List"
111     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
112     attribute = de_push_sequence(service);
113     {
114         uint8_t *a2dProfile = de_push_sequence(attribute);
115         {
116             de_add_number(a2dProfile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_ADVANCED_AUDIO_DISTRIBUTION);
117             de_add_number(a2dProfile,  DE_UINT, DE_SIZE_16, 0x0103);
118         }
119         de_pop_sequence(attribute, a2dProfile);
120     }
121     de_pop_sequence(service, attribute);
122 
123 
124     // 0x0100 "Service Name"
125     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
126     if (service_name){
127         de_add_data(service,  DE_STRING, strlen(service_name), (uint8_t *) service_name);
128     } else {
129         de_add_data(service,  DE_STRING, strlen(default_a2dp_source_service_name), (uint8_t *) default_a2dp_source_service_name);
130     }
131 
132     // 0x0100 "Provider Name"
133     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0102);
134     if (service_provider_name){
135         de_add_data(service,  DE_STRING, strlen(service_provider_name), (uint8_t *) service_provider_name);
136     } else {
137         de_add_data(service,  DE_STRING, strlen(default_a2dp_source_service_provider_name), (uint8_t *) default_a2dp_source_service_provider_name);
138     }
139 
140     // 0x0311 "Supported Features"
141     de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);
142     de_add_number(service, DE_UINT, DE_SIZE_16, supported_features);
143 }
144 
145 
146 static void a2dp_streaming_emit_can_send_media_packet_now(btstack_packet_handler_t callback, uint16_t cid, uint8_t seid){
147     if (!callback) return;
148     uint8_t event[8];
149     int pos = 0;
150     event[pos++] = HCI_EVENT_A2DP_META;
151     event[pos++] = sizeof(event) - 2;
152     event[pos++] = A2DP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW;
153     little_endian_store_16(event, pos, cid);
154     pos += 2;
155     event[pos++] = seid;
156     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
157 }
158 
159 static inline void a2dp_signaling_emit_media_codec_sbc(btstack_packet_handler_t callback, uint8_t * event, uint16_t event_size){
160     if (!callback) return;
161     if (event_size < 18) return;
162     event[0] = HCI_EVENT_A2DP_META;
163     event[2] = A2DP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION;
164     (*callback)(HCI_EVENT_PACKET, 0, event, event_size);
165 }
166 
167 static inline void a2dp_signaling_emit_reject_cmd(btstack_packet_handler_t callback, uint8_t * event, uint16_t event_size){
168     if (!callback) return;
169     if (event_size < 18) return;
170     event[0] = HCI_EVENT_A2DP_META;
171     event[2] = A2DP_SUBEVENT_COMMAND_REJECTED;
172     (*callback)(HCI_EVENT_PACKET, 0, event, event_size);
173 }
174 
175 static void a2dp_signaling_emit_connection_established(btstack_packet_handler_t callback, uint16_t cid, bd_addr_t addr, uint8_t status){
176     if (!callback) return;
177     uint8_t event[12];
178     int pos = 0;
179     event[pos++] = HCI_EVENT_A2DP_META;
180     event[pos++] = sizeof(event) - 2;
181     event[pos++] = A2DP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED;
182     little_endian_store_16(event, pos, cid);
183     pos += 2;
184     reverse_bd_addr(addr,&event[pos]);
185     pos += 6;
186     event[pos++] = status;
187     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
188 }
189 
190 static void a2dp_signaling_emit_control_command(btstack_packet_handler_t callback, uint16_t cid, uint8_t local_seid, uint8_t cmd){
191     if (!callback) return;
192     uint8_t event[6];
193     int pos = 0;
194     event[pos++] = HCI_EVENT_A2DP_META;
195     event[pos++] = sizeof(event) - 2;
196     event[pos++] = cmd;
197     little_endian_store_16(event, pos, cid);
198     pos += 2;
199     event[pos++] = local_seid;
200     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
201 }
202 
203 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
204     UNUSED(channel);
205     UNUSED(size);
206 
207     uint8_t signal_identifier;
208     uint8_t status;
209     uint8_t local_seid;
210     uint8_t remote_seid;
211     uint16_t cid;
212     bd_addr_t address;
213 
214     if (packet_type != HCI_EVENT_PACKET) return;
215     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVDTP_META) return;
216 
217     switch (packet[2]){
218         case AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED:{
219             avdtp_subevent_signaling_connection_established_get_bd_addr(packet, sc.remote_addr);
220             cid = avdtp_subevent_signaling_connection_established_get_avdtp_cid(packet);
221             status = avdtp_subevent_signaling_connection_established_get_status(packet);
222 
223             if (status != 0){
224                 log_info("AVDTP_SUBEVENT_SIGNALING_CONNECTION failed status %d ---", status);
225                 app_state = A2DP_IDLE;
226                 a2dp_signaling_emit_connection_established(a2dp_source_context.a2dp_callback, cid, sc.remote_addr, status);
227                 break;
228             }
229             log_info("A2DP_SUBEVENT_SIGNALING_CONNECTION established avdtp_cid 0x%02x ---", a2dp_source_context.avdtp_cid);
230             sc.active_remote_sep = NULL;
231             sc.active_remote_sep_index = 0;
232             app_state = A2DP_W2_DISCOVER_SEPS;
233             remote_seps_index = 0;
234             memset(remote_seps, 0, sizeof(avdtp_sep_t) * AVDTP_MAX_SEP_NUM);
235             a2dp_signaling_emit_connection_established(a2dp_source_context.a2dp_callback, cid, sc.remote_addr, status);
236             avdtp_source_discover_stream_endpoints(cid);
237             break;
238         }
239 
240         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY:{
241             log_info("A2DP received SBC capability.");
242             if (!sc.local_stream_endpoint) {
243                 log_error("invalid local seid %d", avdtp_subevent_signaling_media_codec_sbc_capability_get_local_seid(packet));
244                 return;
245             }
246             log_info("A2DP received SBC capability.");
247 
248             uint8_t sampling_frequency = avdtp_choose_sbc_sampling_frequency(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_sampling_frequency_bitmap(packet));
249             uint8_t channel_mode = avdtp_choose_sbc_channel_mode(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_channel_mode_bitmap(packet));
250             uint8_t block_length = avdtp_choose_sbc_block_length(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_block_length_bitmap(packet));
251             uint8_t subbands = avdtp_choose_sbc_subbands(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_subbands_bitmap(packet));
252 
253             uint8_t allocation_method = avdtp_choose_sbc_allocation_method(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_allocation_method_bitmap(packet));
254             uint8_t max_bitpool_value = avdtp_choose_sbc_max_bitpool_value(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_max_bitpool_value(packet));
255             uint8_t min_bitpool_value = avdtp_choose_sbc_min_bitpool_value(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_min_bitpool_value(packet));
256 
257             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[0] = (sampling_frequency << 4) | channel_mode;
258             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[1] = (block_length << 4) | (subbands << 2) | allocation_method;
259             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[2] = min_bitpool_value;
260             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[3] = max_bitpool_value;
261 
262             sc.local_stream_endpoint->remote_configuration_bitmap = store_bit16(sc.local_stream_endpoint->remote_configuration_bitmap, AVDTP_MEDIA_CODEC, 1);
263             sc.local_stream_endpoint->remote_configuration.media_codec.media_type = AVDTP_AUDIO;
264             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_type = AVDTP_CODEC_SBC;
265 
266             app_state = A2DP_W2_SET_CONFIGURATION;
267             break;
268         }
269         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CAPABILITY:
270             log_info("received non SBC codec. not implemented");
271             break;
272 
273         case AVDTP_SUBEVENT_SIGNALING_MEDIA_TRANSPORT_CAPABILITY:
274             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_MEDIA_TRANSPORT_CAPABILITY, remote seid %d\n", avdtp_subevent_signaling_media_transport_capability_get_remote_seid(packet));
275             break;
276         case AVDTP_SUBEVENT_SIGNALING_REPORTING_CAPABILITY:
277             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_REPORTING_CAPABILITY, remote seid %d\n", avdtp_subevent_signaling_reporting_capability_get_remote_seid(packet));
278             break;
279         case AVDTP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY:
280             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY, remote seid %d\n", avdtp_subevent_signaling_delay_reporting_capability_get_remote_seid(packet));
281             break;
282         case AVDTP_SUBEVENT_SIGNALING_RECOVERY_CAPABILITY:
283             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_RECOVERY_CAPABILITY, remote seid %d\n", avdtp_subevent_signaling_recovery_capability_get_remote_seid(packet));
284             break;
285         case AVDTP_SUBEVENT_SIGNALING_CONTENT_PROTECTION_CAPABILITY:
286             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_CONTENT_PROTECTION_CAPABILITY, remote seid %d\n", avdtp_subevent_signaling_content_protection_capability_get_remote_seid(packet));
287             break;
288         case AVDTP_SUBEVENT_SIGNALING_HEADER_COMPRESSION_CAPABILITY:
289             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_HEADER_COMPRESSION_CAPABILITY, remote seid %d\n", avdtp_subevent_signaling_header_compression_capability_get_remote_seid(packet));
290             break;
291         case AVDTP_SUBEVENT_SIGNALING_MULTIPLEXING_CAPABILITY:
292             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_MULTIPLEXING_CAPABILITY, remote seid %d\n", avdtp_subevent_signaling_multiplexing_capability_get_remote_seid(packet));
293             break;
294         case AVDTP_SUBEVENT_SIGNALING_CAPABILITY_DONE:
295             break;
296 
297         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION:{
298             // TODO check cid
299             sc.sampling_frequency = avdtp_subevent_signaling_media_codec_sbc_configuration_get_sampling_frequency(packet);
300             sc.block_length = avdtp_subevent_signaling_media_codec_sbc_configuration_get_block_length(packet);
301             sc.subbands = avdtp_subevent_signaling_media_codec_sbc_configuration_get_subbands(packet);
302             sc.allocation_method = avdtp_subevent_signaling_media_codec_sbc_configuration_get_allocation_method(packet) - 1;
303             sc.max_bitpool_value = avdtp_subevent_signaling_media_codec_sbc_configuration_get_max_bitpool_value(packet);
304             sc.channel_mode = avdtp_subevent_signaling_media_codec_sbc_configuration_get_channel_mode(packet);
305             // TODO: deal with reconfigure: avdtp_subevent_signaling_media_codec_sbc_configuration_get_reconfigure(packet);
306             log_info("A2DP received SBC Config: sample rate %u, max bitpool %u.", sc.sampling_frequency, sc.max_bitpool_value);
307             app_state = A2DP_W2_OPEN_STREAM_WITH_SEID;
308             a2dp_signaling_emit_media_codec_sbc(a2dp_source_context.a2dp_callback, packet, size);
309             break;
310         }
311 
312         case AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW:
313             cid = avdtp_subevent_streaming_can_send_media_packet_now_get_avdtp_cid(packet);
314             a2dp_streaming_emit_can_send_media_packet_now(a2dp_source_context.a2dp_callback, cid, 0);
315             break;
316 
317         case AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED:
318             avdtp_subevent_streaming_connection_established_get_bd_addr(packet, address);
319             status = avdtp_subevent_streaming_connection_established_get_status(packet);
320             cid = avdtp_subevent_streaming_connection_established_get_avdtp_cid(packet);
321             remote_seid = avdtp_subevent_streaming_connection_established_get_remote_seid(packet);
322             local_seid  = avdtp_subevent_streaming_connection_established_get_local_seid(packet);
323             if (status != 0){
324                 log_info("AVDTP_SUBEVENT_STREAMING_CONNECTION could not be established, avdtp_cid 0x%02x, status 0x%02x ---", cid, status);
325                 a2dp_streaming_emit_connection_established(a2dp_source_context.a2dp_callback, cid, address, local_seid, remote_seid, status);
326                 break;
327             }
328             log_info("AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED --- avdtp_cid 0x%02x, local seid %d, remote seid %d", cid, local_seid, remote_seid);
329             app_state = A2DP_STREAMING_OPENED;
330             a2dp_streaming_emit_connection_established(a2dp_source_context.a2dp_callback, cid, address, local_seid, remote_seid, 0);
331             break;
332 
333         case AVDTP_SUBEVENT_SIGNALING_SEP_FOUND:{
334             avdtp_sep_t sep;
335             sep.seid = avdtp_subevent_signaling_sep_found_get_remote_seid(packet);;
336             sep.in_use = avdtp_subevent_signaling_sep_found_get_in_use(packet);
337             sep.media_type = (avdtp_media_type_t) avdtp_subevent_signaling_sep_found_get_media_type(packet);
338             sep.type = (avdtp_sep_type_t) avdtp_subevent_signaling_sep_found_get_sep_type(packet);
339             log_info("Found sep: seid %u, in_use %d, media type %d, sep type %d (1-SNK)", sep.seid, sep.in_use, sep.media_type, sep.type);
340             remote_seps[remote_seps_index++] = sep;
341             break;
342         }
343         case AVDTP_SUBEVENT_SIGNALING_SEP_DICOVERY_DONE:
344             app_state = A2DP_W2_GET_CAPABILITIES;
345             sc.active_remote_sep_index = 0;
346             break;
347 
348         case AVDTP_SUBEVENT_SIGNALING_ACCEPT:
349             // TODO check cid
350             signal_identifier = avdtp_subevent_signaling_accept_get_signal_identifier(packet);
351             cid = avdtp_subevent_signaling_accept_get_avdtp_cid(packet);
352             log_info("A2DP Accepted %d, state %d", signal_identifier, app_state);
353 
354             switch (app_state){
355                 case A2DP_W2_GET_CAPABILITIES:
356                     if (sc.active_remote_sep_index < remote_seps_index){
357                         sc.active_remote_sep = &remote_seps[sc.active_remote_sep_index++];
358                         avdtp_source_get_capabilities(cid, sc.active_remote_sep->seid);
359                     }
360                     break;
361                 case A2DP_W2_SET_CONFIGURATION:{
362                     if (!sc.local_stream_endpoint) return;
363                     log_info("A2DP initiate set configuration locally and wait for response ... ");
364                     app_state = A2DP_IDLE;
365                     avdtp_source_set_configuration(cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), sc.active_remote_sep->seid, sc.local_stream_endpoint->remote_configuration_bitmap, sc.local_stream_endpoint->remote_configuration);
366                     break;
367                 }
368                 case A2DP_W2_OPEN_STREAM_WITH_SEID:{
369                     log_info("A2DP open stream ");
370                     app_state = A2DP_W4_OPEN_STREAM_WITH_SEID;
371                     avdtp_source_open_stream(cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), sc.active_remote_sep->seid);
372                     break;
373                 }
374                 case A2DP_STREAMING_OPENED:
375                     if (!a2dp_source_context.a2dp_callback) return;
376                     switch (signal_identifier){
377                         case  AVDTP_SI_START:
378                             a2dp_signaling_emit_control_command(a2dp_source_context.a2dp_callback, cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), A2DP_SUBEVENT_STREAM_STARTED);
379                             break;
380                         case AVDTP_SI_SUSPEND:
381                             a2dp_signaling_emit_control_command(a2dp_source_context.a2dp_callback, cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), A2DP_SUBEVENT_STREAM_SUSPENDED);
382                             break;
383                         case AVDTP_SI_ABORT:
384                         case AVDTP_SI_CLOSE:
385                             a2dp_signaling_emit_control_command(a2dp_source_context.a2dp_callback, cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), A2DP_SUBEVENT_STREAM_STOPPED);
386                             break;
387                         default:
388                             break;
389                     }
390                     break;
391                 default:
392                     app_state = A2DP_IDLE;
393                     break;
394             }
395 
396             break;
397         case AVDTP_SUBEVENT_SIGNALING_REJECT:
398         case AVDTP_SUBEVENT_SIGNALING_GENERAL_REJECT:
399             app_state = A2DP_IDLE;
400             a2dp_signaling_emit_reject_cmd(a2dp_source_context.a2dp_callback, packet, size);
401             break;
402         case AVDTP_SUBEVENT_SIGNALING_CONNECTION_RELEASED:{
403             app_state = A2DP_IDLE;
404             uint8_t event[6];
405             int pos = 0;
406             event[pos++] = HCI_EVENT_A2DP_META;
407             event[pos++] = sizeof(event) - 2;
408             event[pos++] = A2DP_SUBEVENT_SIGNALING_CONNECTION_RELEASED;
409             little_endian_store_16(event, pos, avdtp_subevent_streaming_connection_released_get_avdtp_cid(packet));
410             pos += 2;
411             event[pos++] = avdtp_subevent_streaming_connection_released_get_local_seid(packet);
412             (*a2dp_source_context.a2dp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
413             break;
414         }
415         case AVDTP_SUBEVENT_STREAMING_CONNECTION_RELEASED:{
416             app_state = A2DP_IDLE;
417             uint8_t event[6];
418             int pos = 0;
419             event[pos++] = HCI_EVENT_A2DP_META;
420             event[pos++] = sizeof(event) - 2;
421             event[pos++] = A2DP_SUBEVENT_STREAM_RELEASED;
422             little_endian_store_16(event, pos, avdtp_subevent_streaming_connection_released_get_avdtp_cid(packet));
423             pos += 2;
424             event[pos++] = avdtp_subevent_streaming_connection_released_get_local_seid(packet);
425             (*a2dp_source_context.a2dp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
426             break;
427         }
428         default:
429             app_state = A2DP_IDLE;
430             log_info("not implemented");
431             break;
432     }
433 }
434 void a2dp_source_register_packet_handler(btstack_packet_handler_t callback){
435     if (callback == NULL){
436         log_error("a2dp_source_register_packet_handler called with NULL callback");
437         return;
438     }
439     avdtp_source_register_packet_handler(&packet_handler);
440     a2dp_source_context.a2dp_callback = callback;
441 }
442 
443 void a2dp_source_init(void){
444     avdtp_source_init(&a2dp_source_context);
445 }
446 
447 avdtp_stream_endpoint_t * a2dp_source_create_stream_endpoint(avdtp_media_type_t media_type, avdtp_media_codec_type_t media_codec_type,
448     uint8_t * codec_capabilities, uint16_t codec_capabilities_len,
449     uint8_t * media_codec_info, uint16_t media_codec_info_len){
450     avdtp_stream_endpoint_t * local_stream_endpoint = avdtp_source_create_stream_endpoint(AVDTP_SOURCE, media_type);
451     if (!local_stream_endpoint){
452         return NULL;
453     }
454     avdtp_source_register_media_transport_category(avdtp_stream_endpoint_seid(local_stream_endpoint));
455     avdtp_source_register_media_codec_category(avdtp_stream_endpoint_seid(local_stream_endpoint), media_type, media_codec_type,
456         codec_capabilities, codec_capabilities_len);
457     local_stream_endpoint->remote_configuration.media_codec.media_codec_information     = media_codec_info;
458     local_stream_endpoint->remote_configuration.media_codec.media_codec_information_len = media_codec_info_len;
459     sc.local_stream_endpoint = local_stream_endpoint;
460     return local_stream_endpoint;
461 }
462 
463 uint8_t a2dp_source_establish_stream(bd_addr_t remote_addr, uint8_t loc_seid, uint16_t * a2dp_cid){
464     sc.local_stream_endpoint = avdtp_stream_endpoint_for_seid(loc_seid, &a2dp_source_context);
465     if (!sc.local_stream_endpoint){
466         log_error(" no local_stream_endpoint for seid %d", loc_seid);
467         return AVDTP_SEID_DOES_NOT_EXIST;
468     }
469     memcpy(sc.remote_addr, remote_addr, 6);
470     return avdtp_source_connect(remote_addr, a2dp_cid);
471 }
472 
473 uint8_t a2dp_source_disconnect(uint16_t a2dp_cid){
474     return avdtp_disconnect(a2dp_cid, &a2dp_source_context);
475 }
476 
477 uint8_t a2dp_source_start_stream(uint16_t a2dp_cid, uint8_t local_seid){
478     return avdtp_start_stream(a2dp_cid, local_seid, &a2dp_source_context);
479 }
480 
481 uint8_t a2dp_source_pause_stream(uint16_t a2dp_cid, uint8_t local_seid){
482     return avdtp_suspend_stream(a2dp_cid, local_seid, &a2dp_source_context);
483 }
484 
485 static void a2dp_source_setup_media_header(uint8_t * media_packet, int size, int *offset, uint8_t marker, uint16_t sequence_number){
486     if (size < AVDTP_MEDIA_PAYLOAD_HEADER_SIZE){
487         log_error("small outgoing buffer");
488         return;
489     }
490 
491     uint8_t  rtp_version = 2;
492     uint8_t  padding = 0;
493     uint8_t  extension = 0;
494     uint8_t  csrc_count = 0;
495     uint8_t  payload_type = 0x60;
496     // uint16_t sequence_number = stream_endpoint->sequence_number;
497     uint32_t timestamp = btstack_run_loop_get_time_ms();
498     uint32_t ssrc = 0x11223344;
499 
500     // rtp header (min size 12B)
501     int pos = 0;
502     // int mtu = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
503 
504     media_packet[pos++] = (rtp_version << 6) | (padding << 5) | (extension << 4) | csrc_count;
505     media_packet[pos++] = (marker << 1) | payload_type;
506     big_endian_store_16(media_packet, pos, sequence_number);
507     pos += 2;
508     big_endian_store_32(media_packet, pos, timestamp);
509     pos += 4;
510     big_endian_store_32(media_packet, pos, ssrc); // only used for multicast
511     pos += 4;
512     *offset = pos;
513 }
514 
515 void a2dp_source_stream_endpoint_request_can_send_now(uint16_t a2dp_cid, uint8_t local_seid){
516     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
517     if (!stream_endpoint) {
518         log_error("A2DP source: no stream_endpoint with seid %d", local_seid);
519         return;
520     }
521     if (a2dp_source_context.avdtp_cid != a2dp_cid){
522         log_error("A2DP source: a2dp cid 0x%02x not known, expected 0x%02x", a2dp_cid, a2dp_source_context.avdtp_cid);
523         return;
524     }
525     stream_endpoint->send_stream = 1;
526     avdtp_request_can_send_now_initiator(stream_endpoint->connection, stream_endpoint->l2cap_media_cid);
527 }
528 
529 int a2dp_max_media_payload_size(uint16_t a2dp_cid, uint8_t local_seid){
530     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
531     if (!stream_endpoint) {
532         log_error("A2DP source: no stream_endpoint with seid %d", local_seid);
533         return 0;
534     }
535     if (a2dp_source_context.avdtp_cid != a2dp_cid){
536         log_error("A2DP source: a2dp cid 0x%02x not known, expected 0x%02x", a2dp_cid, a2dp_source_context.avdtp_cid);
537         return 0;
538     }
539 
540     if (stream_endpoint->l2cap_media_cid == 0){
541         log_error("A2DP source: no media connection for seid %d", local_seid);
542         return 0;
543     }
544     return l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid) - AVDTP_MEDIA_PAYLOAD_HEADER_SIZE;
545 }
546 
547 static void a2dp_source_copy_media_payload(uint8_t * media_packet, int size, int * offset, uint8_t * storage, int num_bytes_to_copy, uint8_t num_frames){
548     if (size < num_bytes_to_copy + 1){
549         log_error("small outgoing buffer: buffer size %u, but need %u", size, num_bytes_to_copy + 1);
550         return;
551     }
552 
553     int pos = *offset;
554     media_packet[pos++] = num_frames; // (fragmentation << 7) | (starting_packet << 6) | (last_packet << 5) | num_frames;
555     memcpy(media_packet + pos, storage, num_bytes_to_copy);
556     pos += num_bytes_to_copy;
557     *offset = pos;
558 }
559 
560 int a2dp_source_stream_send_media_payload(uint16_t a2dp_cid, uint8_t local_seid, uint8_t * storage, int num_bytes_to_copy, uint8_t num_frames, uint8_t marker){
561     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
562     if (!stream_endpoint) {
563         log_error("A2DP source: no stream_endpoint with seid %d", local_seid);
564         return 0;
565     }
566     if (a2dp_source_context.avdtp_cid != a2dp_cid){
567         log_error("A2DP source: a2dp cid 0x%02x not known, expected 0x%02x", a2dp_cid, a2dp_source_context.avdtp_cid);
568         return 0;
569     }
570 
571     if (stream_endpoint->l2cap_media_cid == 0){
572         log_error("A2DP source: no media connection for seid %d", local_seid);
573         return 0;
574     }
575 
576     int size = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
577     int offset = 0;
578 
579     l2cap_reserve_packet_buffer();
580     uint8_t * media_packet = l2cap_get_outgoing_buffer();
581     //int size = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
582     a2dp_source_setup_media_header(media_packet, size, &offset, marker, stream_endpoint->sequence_number);
583     a2dp_source_copy_media_payload(media_packet, size, &offset, storage, num_bytes_to_copy, num_frames);
584     stream_endpoint->sequence_number++;
585     l2cap_send_prepared(stream_endpoint->l2cap_media_cid, offset);
586     return size;
587 }
588