Use 48kHz SBC instead of 44.1

lib/bt/host/bluedroid/btc/profile/std/a2dp/bta_av_co.c

@@ -70,7 +70,7 @@ const UINT8 bta_av_co_cp_scmst[BTA_AV_CP_INFO_LEN] = "\x02\x02\x00";
 
 /* SBC SRC codec capabilities */
 const tA2D_SBC_CIE bta_av_co_sbc_caps = {
-    (A2D_SBC_IE_SAMP_FREQ_44), /* samp_freq */
+    (A2D_SBC_IE_SAMP_FREQ_44 | A2D_SBC_IE_SAMP_FREQ_48), /* samp_freq */
     (A2D_SBC_IE_CH_MD_MONO | A2D_SBC_IE_CH_MD_STEREO | A2D_SBC_IE_CH_MD_JOINT | A2D_SBC_IE_CH_MD_DUAL), /* ch_mode */
     (A2D_SBC_IE_BLOCKS_16 | A2D_SBC_IE_BLOCKS_12 | A2D_SBC_IE_BLOCKS_8 | A2D_SBC_IE_BLOCKS_4), /* block_len */
     (A2D_SBC_IE_SUBBAND_4 | A2D_SBC_IE_SUBBAND_8), /* num_subbands */
@@ -91,7 +91,7 @@ const tA2D_SBC_CIE bta_av_co_sbc_sink_caps = {
 };
 
 #if !defined(BTC_AV_SBC_DEFAULT_SAMP_FREQ)
-#define BTC_AV_SBC_DEFAULT_SAMP_FREQ A2D_SBC_IE_SAMP_FREQ_44
+#define BTC_AV_SBC_DEFAULT_SAMP_FREQ A2D_SBC_IE_SAMP_FREQ_48
 #endif
 
 /* Default SBC codec configuration */

lib/bt/host/bluedroid/btc/profile/std/a2dp/btc_a2dp_source.c

@@ -441,8 +441,8 @@ void btc_a2dp_source_setup_codec(void)
 
     osi_mutex_global_lock();
 
-    /* for now hardcode 44.1 khz 16 bit stereo PCM format */
-    media_feeding.cfg.pcm.sampling_freq = 44100;
+    /* for now hardcode 48 khz 16 bit stereo PCM format */
+    media_feeding.cfg.pcm.sampling_freq = 48000;
     media_feeding.cfg.pcm.bit_per_sample = 16;
     media_feeding.cfg.pcm.num_channel = 2;
     media_feeding.format = BTC_AV_CODEC_PCM;

src/audio/bt_audio_output.cpp

@@ -83,7 +83,7 @@ auto BluetoothAudioOutput::PrepareFormat(const Format& orig) -> Format {
   // ESP-IDF's current Bluetooth implementation currently handles SBC encoding,
   // but requires a fixed input format.
   return Format{
-      .sample_rate = 44100,
+      .sample_rate = 48000,
       .num_channels = 2,
       .bits_per_sample = 16,
   };