diff --git a/src/classic/a2dp_source.c b/src/classic/a2dp_source.c
index ed28a24a3..4d8cd783c 100644
--- a/src/classic/a2dp_source.c
+++ b/src/classic/a2dp_source.c
@@ -52,7 +52,6 @@
 #include "l2cap.h"
 
 #define AVDTP_MAX_SEP_NUM 10
-#define AVDTP_MEDIA_PAYLOAD_HEADER_SIZE 12
 
 static const char * default_a2dp_source_service_name = "BTstack A2DP Source Service";
 static const char * default_a2dp_source_service_provider_name = "BTstack A2DP Source Service Provider";
@@ -581,106 +580,14 @@ uint8_t a2dp_source_pause_stream(uint16_t a2dp_cid, uint8_t local_seid){
     return avdtp_suspend_stream(a2dp_cid, local_seid, &a2dp_source_context);
 }
 
-static void a2dp_source_setup_media_header(uint8_t * media_packet, int size, int *offset, uint8_t marker, uint16_t sequence_number){
-    if (size < AVDTP_MEDIA_PAYLOAD_HEADER_SIZE){
-        log_error("small outgoing buffer");
-        return;
-    }
-
-    uint8_t  rtp_version = 2;
-    uint8_t  padding = 0;
-    uint8_t  extension = 0;
-    uint8_t  csrc_count = 0;
-    uint8_t  payload_type = 0x60;
-    // uint16_t sequence_number = stream_endpoint->sequence_number;
-    uint32_t timestamp = btstack_run_loop_get_time_ms();
-    uint32_t ssrc = 0x11223344;
-
-    // rtp header (min size 12B)
-    int pos = 0;
-    // int mtu = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
-
-    media_packet[pos++] = (rtp_version << 6) | (padding << 5) | (extension << 4) | csrc_count;
-    media_packet[pos++] = (marker << 1) | payload_type;
-    big_endian_store_16(media_packet, pos, sequence_number);
-    pos += 2;
-    big_endian_store_32(media_packet, pos, timestamp);
-    pos += 4;
-    big_endian_store_32(media_packet, pos, ssrc); // only used for multicast
-    pos += 4;
-    *offset = pos;
-}
-
 void a2dp_source_stream_endpoint_request_can_send_now(uint16_t a2dp_cid, uint8_t local_seid){
-    if (a2dp_source_context.avdtp_cid != a2dp_cid){
-        log_error("A2DP source: a2dp cid 0x%02x not known, expected 0x%02x", a2dp_cid, a2dp_source_context.avdtp_cid);
-        return;
-    }
-    avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
-    if (!stream_endpoint) {
-        log_error("A2DP source: no stream_endpoint with seid %d", local_seid);
-        return;
-    }
-    stream_endpoint->send_stream = 1;
-    avdtp_request_can_send_now_initiator(stream_endpoint->connection, stream_endpoint->l2cap_media_cid);
+    avdtp_source_stream_endpoint_request_can_send_now(a2dp_cid, local_seid);
 }
 
 int a2dp_max_media_payload_size(uint16_t a2dp_cid, uint8_t local_seid){
-    if (a2dp_source_context.avdtp_cid != a2dp_cid){
-        log_error("A2DP source: a2dp cid 0x%02x not known, expected 0x%02x", a2dp_cid, a2dp_source_context.avdtp_cid);
-        return 0;
-    }
-    avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
-    if (!stream_endpoint) {
-        log_error("A2DP source: no stream_endpoint with seid %d", local_seid);
-        return 0;
-    }
-    
-    if (stream_endpoint->l2cap_media_cid == 0){
-        log_error("A2DP source: no media connection for seid %d", local_seid);
-        return 0;
-    }  
-    return l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid) - AVDTP_MEDIA_PAYLOAD_HEADER_SIZE;
-}
-
-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){
-    if (size < num_bytes_to_copy + 1){
-        log_error("small outgoing buffer: buffer size %u, but need %u", size, num_bytes_to_copy + 1);
-        return;
-    }
-    
-    int pos = *offset;
-    media_packet[pos++] = num_frames; // (fragmentation << 7) | (starting_packet << 6) | (last_packet << 5) | num_frames;
-    memcpy(media_packet + pos, storage, num_bytes_to_copy);
-    pos += num_bytes_to_copy;
-    *offset = pos;
+    return avdtp_max_media_payload_size(a2dp_cid, local_seid);
 }
 
 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){
-    if (a2dp_source_context.avdtp_cid != a2dp_cid){
-        log_error("A2DP source: a2dp cid 0x%02x not known, expected 0x%02x", a2dp_cid, a2dp_source_context.avdtp_cid);
-        return 0;
-    }
-    avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
-    if (!stream_endpoint) {
-        log_error("A2DP source: no stream_endpoint with seid %d", local_seid);
-        return 0;
-    }
-    
-    if (stream_endpoint->l2cap_media_cid == 0){
-        log_error("A2DP source: no media connection for seid %d", local_seid);
-        return 0;
-    } 
-
-    int size = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
-    int offset = 0;
-
-    l2cap_reserve_packet_buffer();
-    uint8_t * media_packet = l2cap_get_outgoing_buffer();
-    //int size = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
-    a2dp_source_setup_media_header(media_packet, size, &offset, marker, stream_endpoint->sequence_number);
-    a2dp_source_copy_media_payload(media_packet, size, &offset, storage, num_bytes_to_copy, num_frames);
-    stream_endpoint->sequence_number++;
-    l2cap_send_prepared(stream_endpoint->l2cap_media_cid, offset);
-    return size;
+    return avdtp_source_stream_send_media_payload(a2dp_cid, local_seid, storage, num_bytes_to_copy, num_frames, marker);
 }