squeezelite-esp32/components/squeezelite/decode_bt.c

/* 
 *  Squeezelite for esp32
 *
 *  (c) Sebastien 2019
 *      Philippe G. 2019, philippe_44@outlook.com
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
 
#include "squeezelite.h"
#include "bt_app_sink.h"

#define LOCK_O   mutex_lock(outputbuf->mutex)
#define UNLOCK_O mutex_unlock(outputbuf->mutex)
#define LOCK_D   mutex_lock(decode.mutex);
#define UNLOCK_D mutex_unlock(decode.mutex);

extern struct outputstate output;
extern struct decodestate decode;
extern struct buffer *outputbuf;
// this is the only system-wide loglevel variable
extern log_level loglevel;

/****************************************************************************************
 * BT sink data handler
 */
static void bt_sink_data_handler(const uint8_t *data, uint32_t len)
{
    size_t bytes;
	
	// would be better to lock decoder, but really, it does not matter
	if (decode.state != DECODE_STOPPED) {
		LOG_SDEBUG("Cannot use BT sink while LMS is controlling player");
		return;
	} 
	
	// there will always be room at some point
	while (len) {
		LOCK_O;
		
		bytes = min(len, _buf_cont_write(outputbuf));
#if BYTES_PER_FRAME == 4
		memcpy(outputbuf->writep, data, bytes);
#else
		{
			s16_t *iptr = (s16_t*) data;
			ISAMPLE_T *optr = (ISAMPLE_T*) outputbuf->writep;
			size_t n = bytes / BYTES_PER_FRAME * 2;
			while (n--) *optr++ = *iptr++ << 16;
		}
#endif	
		_buf_inc_writep(outputbuf, bytes);
		len -= bytes;
		data += bytes;
				
		UNLOCK_O;
		
		// allow i2s to empty the buffer if needed
		if (len) usleep(50000);
	}	
}

/****************************************************************************************
 * BT sink command handler
 */
static void bt_sink_cmd_handler(bt_sink_cmd_t cmd, ...) 
{
	va_list args;
	
	LOCK_D;
	if (decode.state != DECODE_STOPPED) {
		LOG_WARN("Cannot use BT sink while LMS is controlling player");
		UNLOCK_D;
		return;
	} 	
	
	va_start(args, cmd);
	
	if (cmd != BT_SINK_VOLUME) LOCK_O;
		
	switch(cmd) {
	case BT_SINK_CONNECTED:
		output.state = OUTPUT_STOPPED;
		LOG_INFO("BT sink started");
		break;
	case BT_SINK_DISCONNECTED:	
		output.state = OUTPUT_OFF;
		LOG_INFO("BT sink stopped");
		break;
	case BT_SINK_PLAY:
		output.state = OUTPUT_EXTERNAL;
		LOG_INFO("BT sink playing");
		break;
	case BT_SINK_PAUSE:		
	case BT_SINK_STOP:
		output.state = OUTPUT_STOPPED;
		LOG_INFO("BT sink stopped");
		break;
	case BT_SINK_RATE:
		output.current_sample_rate = va_arg(args, u32_t);
		LOG_INFO("Setting BT sample rate %u", output.current_sample_rate);
		break;
	case BT_SINK_VOLUME: {
		u16_t volume = (u16_t) va_arg(args, u32_t);
		volume *= 65536 / 128;
		set_volume(volume, volume);
		break;
	}
	}
	
	if (cmd != BT_SINK_VOLUME) UNLOCK_O;
	UNLOCK_D;

	va_end(args);
}
 
/****************************************************************************************
 * We provide the generic codec register option
 */
void register_other(void) {
#ifdef CONFIG_BT_SINK	
	if (!strcasestr(output.device, "BT ")) {
		bt_sink_init(bt_sink_cmd_handler, bt_sink_data_handler);
		LOG_INFO("Initializing BT sink");
	} else {
		LOG_WARN("Cannot be a BT sink and source");
	}	
#endif	
}