I am trying to make my gateway send stereo data to the headset where it will be played on an external codec. I want this to be a single stereo stream.
I had this working in SDK 2.5.1 but can't seem to get it working with SDK 2.6.1.
The gateway is an unmodified nrf5340 audio DK using the standard board files.
The headset is also an nrf5430 audio DK with an external codec wired up. It uses a Zephyr board file to keep the codec interface line high (codec LED is orange). The headset code does not use the cirrus_cs47l63 driver (#def'd out with CONFIG_HW_CODEC_CIRRUS_LOGIC), my external codec is being configured externally.
I've added STEREO_CIS_HEADSET to my KConfig and set it in prj.conf along with:
In unicast_server\Kconfig.defaults, I modified LC3_DEC_CHAN_MAX:
In audio_system.c, audio_headset_configure, I added
#endif /* (CONFIG_STREAM_BIDIRECTIONAL) */
if (IS_ENABLED(CONFIG_STEREO_CIS_HEADSET)) {
sw_codec_cfg.decoder.num_ch = 2;
sw_codec_cfg.decoder.channel_mode = SW_CODEC_STEREO;
} else {
sw_codec_cfg.decoder.num_ch = 1;
sw_codec_cfg.decoder.channel_mode = SW_CODEC_MONO;
}
In bt_le_audio_tx.c, bt_le_audio_tx_send, I modified
if (streams_to_tx > SRC_STREAM_COUNT) {
return -ENOMEM;
}
if (IS_ENABLED(CONFIG_STEREO_CIS_HEADSET)) {
data_size_pr_stream = enc_audio.size;
} else {
if ((enc_audio.num_ch == 1) || (enc_audio.num_ch == streams_to_tx)) {
data_size_pr_stream = enc_audio.size / enc_audio.num_ch;
} else {
LOG_ERR("Num encoded channels must be 1 or equal to num streams");
return -EINVAL;
}
}
which led to runtime errors in the gateway about "The encoded data size does not match the SDU size"
where data_size_pr_stream was 120, LE_AUDIO_SDU_SIZE_OCTETS(bitrate) was 60, and bitrate was 48000.
I commended out the error, further down in the same function:
// if (data_size_pr_stream != LE_AUDIO_SDU_SIZE_OCTETS(bitrate)) {
// LOG_ERR("The encoded data size does not match the SDU size");
// return -EINVAL;
// }In unicast_client.c, at the top, I added
static struct bt_audio_codec_qos lc3_preset_sink_stereo_qos = BT_AUDIO_CODEC_LC3_QOS_10_UNFRAMED( LE_AUDIO_SDU_SIZE_OCTETS(CONFIG_BT_AUDIO_BITRATE_UNICAST_SINK) * 2, CONFIG_BT_AUDIO_RETRANSMITS, CONFIG_BT_AUDIO_MAX_TRANSPORT_LATENCY_MS, CONFIG_BT_AUDIO_PRESENTATION_DELAY_US);
and then later in the same file, in unicast_client_enable I added the pointer to lc3_preset_sink_stereo_qos:
if ((i % 2) == 0) {
if (IS_ENABLED(CONFIG_STEREO_CIS_HEADSET)) {
group_stream_params[i].qos = &lc3_preset_sink_stereo_qos;
} else {
group_stream_params[i].qos = &lc3_preset_sink.qos;
}
group_stream_params[i].stream = &headsets[headset_iterator].sink_stream;
In unicast_server.c, near the top, I added the two channels support:
static struct bt_audio_codec_cap lc3_codec_sink = BT_AUDIO_CODEC_CAP_LC3( BT_AUDIO_CODEC_CAPABILIY_FREQ, (BT_AUDIO_CODEC_LC3_DURATION_10 | BT_AUDIO_CODEC_LC3_DURATION_PREFER_10), #if CONFIG_STEREO_CIS_HEADSET BT_AUDIO_CODEC_LC3_CHAN_COUNT_SUPPORT(2), #else BT_AUDIO_CODEC_LC3_CHAN_COUNT_SUPPORT(1), #endif /* CONFIG_STEREO_CIS_HEADSET */ LE_AUDIO_SDU_SIZE_OCTETS(CONFIG_LC3_BITRATE_MIN), LE_AUDIO_SDU_SIZE_OCTETS(CONFIG_LC3_BITRATE_MAX), 1u, AVAILABLE_SINK_CONTEXT);
I made no changes to the child image.
Using a logic analyzer on my headset-to-codec I2S connection I can see that only one channel of data is being sent from the gateway tones mode. (Once tones works, I will hook the gateway up to USB and get stereo audio from my computer.)
As I said, I had this working in 2.5.1 based on reading past forum posts but can't get it in 2.6.1. Advice would be greatly appreciated.
Thank you very much,
ECW
