multi-client support

.github/iwyu.imp

@@ -41,4 +41,6 @@
 
 	{ include: [ '<spandsp/plc.h>', private, '<spandsp.h>', public ] },
 
+	{ include: [ '<bits/types/struct_itimerspec.h>', private, '<sys/timerfd.h>', public ] },
+
 ]

.github/spellcheck-wordlist.txt

@@ -157,6 +157,8 @@ BTRH
 BTT
 bttransport
 btusb
+# aspell considers PIPE_BUF to be 2 words :(
+BUF
 CCE
 CIEV
 CIND
@@ -183,6 +185,7 @@ ENODEV
 EP
 EPIPE
 EPMR
+epoll
 EQMID
 errno
 FB

doc/bluealsa.8.rst

@@ -58,6 +58,12 @@ OPTIONS
     Without this option, **bluealsa** registers itself as an "org.bluealsa"
     D-Bus service.  For more information see the EXAMPLES_ below.
 
+-M, --multi-client
+    Permit multiple clients to connect to the same PCM stream.
+    Without this option, only one client can connect to a PCM.
+    With this option, for playback clients, the streams are mixed together;
+    for capture each client receives a copy of the stream.
+
 -i hciX, --device=hciX
     HCI device to use. Can be specified multiple times to select more than one
     HCI.  Because HCI numbering can change after a system reboot, this option

src/Makefile.am

@@ -35,6 +35,9 @@ bluealsa_SOURCES = \
 	ba-transport-pcm.c \
 	bluealsa-dbus.c \
 	bluealsa-iface.xml \
+	bluealsa-mix-buffer.c \
+	bluealsa-pcm-client.c \
+	bluealsa-pcm-multi.c \
 	bluez.c \
 	bluez-iface.xml \
 	codec-sbc.c \

src/a2dp-aac.c

@@ -30,6 +30,7 @@
 #include "ba-config.h"
 #include "ba-transport.h"
 #include "ba-transport-pcm.h"
+#include "bluealsa-pcm-multi.h"
 #include "io.h"
 #include "rtp.h"
 #include "utils.h"
@@ -195,6 +196,11 @@ void *a2dp_aac_enc_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	rtp_header_t *rtp_header;
 	/* initialize RTP header and get anchor for payload */
 	uint8_t *rtp_payload = rtp_a2dp_init(bt.data, &rtp_header, NULL, 0);
@@ -375,6 +381,11 @@ void *a2dp_aac_dec_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	struct rtp_state rtp = { .synced = false };
 	/* RTP clock frequency equal to 90kHz */
 	rtp_state_init(&rtp, samplerate, 90000);

src/a2dp-aptx-hd.c

@@ -26,6 +26,7 @@
 #include "ba-config.h"
 #include "ba-transport.h"
 #include "ba-transport-pcm.h"
+#include "bluealsa-pcm-multi.h"
 #include "codec-aptx.h"
 #include "io.h"
 #include "rtp.h"
@@ -67,6 +68,11 @@ void *a2dp_aptx_hd_enc_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	rtp_header_t *rtp_header;
 	/* initialize RTP header and get anchor for payload */
 	uint8_t *rtp_payload = rtp_a2dp_init(bt.data, &rtp_header, NULL, 0);
@@ -200,6 +206,11 @@ void *a2dp_aptx_hd_dec_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	struct rtp_state rtp = { .synced = false };
 	/* RTP clock frequency equal to audio samplerate */
 	rtp_state_init(&rtp, samplerate, samplerate);

src/a2dp-aptx.c

@@ -25,6 +25,7 @@
 #include "ba-config.h"
 #include "ba-transport.h"
 #include "ba-transport-pcm.h"
+#include "bluealsa-pcm-multi.h"
 #include "codec-aptx.h"
 #include "io.h"
 #include "shared/a2dp-codecs.h"
@@ -64,6 +65,11 @@ void *a2dp_aptx_enc_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	debug_transport_pcm_thread_loop(t_pcm, "START");
 	for (ba_transport_pcm_state_set_running(t_pcm);;) {
 
@@ -178,6 +184,11 @@ void *a2dp_aptx_dec_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	debug_transport_pcm_thread_loop(t_pcm, "START");
 	for (ba_transport_pcm_state_set_running(t_pcm);;) {
 

src/a2dp-faststream.c

@@ -24,6 +24,7 @@
 #include "ba-config.h"
 #include "ba-transport.h"
 #include "ba-transport-pcm.h"
+#include "bluealsa-pcm-multi.h"
 #include "codec-sbc.h"
 #include "io.h"
 #include "shared/a2dp-codecs.h"
@@ -67,6 +68,11 @@ void *a2dp_faststream_enc_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	debug_transport_pcm_thread_loop(t_pcm, "START");
 	for (ba_transport_pcm_state_set_running(t_pcm);;) {
 
@@ -187,6 +193,11 @@ void *a2dp_faststream_dec_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	debug_transport_pcm_thread_loop(t_pcm, "START");
 	for (ba_transport_pcm_state_set_running(t_pcm);;) {
 

src/a2dp-ldac.c

@@ -27,6 +27,7 @@
 #include "ba-transport.h"
 #include "ba-transport-pcm.h"
 #include "ba-config.h"
+#include "bluealsa-pcm-multi.h"
 #include "io.h"
 #include "rtp.h"
 #include "utils.h"
@@ -92,6 +93,11 @@ void *a2dp_ldac_enc_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	rtp_header_t *rtp_header;
 	rtp_media_header_t *rtp_media_header;
 	/* initialize RTP headers and get anchor for payload */
@@ -249,6 +255,11 @@ void *a2dp_ldac_dec_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	struct rtp_state rtp = { .synced = false };
 	/* RTP clock frequency equal to audio samplerate */
 	rtp_state_init(&rtp, samplerate, samplerate);

src/a2dp-mpeg.c

@@ -35,6 +35,7 @@
 #include "ba-config.h"
 #include "ba-transport.h"
 #include "ba-transport-pcm.h"
+#include "bluealsa-pcm-multi.h"
 #include "io.h"
 #include "rtp.h"
 #include "utils.h"
@@ -151,6 +152,11 @@ void *a2dp_mp3_enc_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	rtp_header_t *rtp_header;
 	rtp_mpeg_audio_header_t *rtp_mpeg_audio_header;
 	/* initialize RTP headers and get anchor for payload */
@@ -336,6 +342,11 @@ void *a2dp_mpeg_dec_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	struct rtp_state rtp = { .synced = false };
 	/* RTP clock frequency equal to 90kHz */
 	rtp_state_init(&rtp, samplerate, 90000);

src/a2dp-sbc.c

@@ -29,6 +29,7 @@
 #include "ba-transport.h"
 #include "ba-transport-pcm.h"
 #include "ba-config.h"
+#include "bluealsa-pcm-multi.h"
 #include "codec-sbc.h"
 #include "io.h"
 #include "rtp.h"
@@ -94,6 +95,11 @@ void *a2dp_sbc_enc_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	rtp_header_t *rtp_header;
 	rtp_media_header_t *rtp_media_header;
 
@@ -237,6 +243,11 @@ void *a2dp_sbc_dec_thread(struct ba_transport_pcm *t_pcm) {
 		goto fail_ffb;
 	}
 
+	/* start multi client thread if required. */
+	if (t_pcm->multi &&
+			!bluealsa_pcm_multi_init(t_pcm->multi, pcm.nmemb))
+		goto fail_ffb;
+
 	struct rtp_state rtp = { .synced = false };
 	/* RTP clock frequency equal to audio samplerate */
 	rtp_state_init(&rtp, samplerate, samplerate);

src/ba-config.c

@@ -41,6 +41,8 @@ struct ba_config config = {
 
 	.disable_realtek_usb_fix = false,
 
+	.multi_enabled = false,
+
 	/* CVSD is a mandatory codec */
 	.hfp.codecs.cvsd = true,
 #if ENABLE_MSBC

src/ba-config.h

@@ -75,6 +75,9 @@ struct ba_config {
 	/* disable alt-3 MTU for mSBC with Realtek USB adapters */
 	bool disable_realtek_usb_fix;
 
+	/* Is multi client support enabled? */
+	bool multi_enabled;
+
 	struct {
 
 		/* available HFP codecs */

src/ba-transport-pcm.c

@@ -32,6 +32,7 @@
 #include "ba-rfcomm.h"
 #include "ba-transport.h"
 #include "bluealsa-dbus.h"
+#include "bluealsa-pcm-multi.h"
 #include "bluez-iface.h"
 #include "bluez.h"
 #include "dbus.h"
@@ -77,6 +78,9 @@ int transport_pcm_init(
 	pcm->pipe[0] = -1;
 	pcm->pipe[1] = -1;
 
+	pcm->multi = NULL;
+	pcm->paused = false;
+
 	pcm->volume[0].level = config.volume_init_level;
 	pcm->volume[1].level = config.volume_init_level;
 	ba_transport_pcm_volume_set(&pcm->volume[0], NULL, NULL, NULL);
@@ -97,6 +101,9 @@ int transport_pcm_init(
 			t->d->ba_dbus_path, transport_get_dbus_path_type(t->profile),
 			mode == BA_TRANSPORT_PCM_MODE_SOURCE ? "source" : "sink");
 
+	if (bluealsa_pcm_multi_enabled(t))
+		pcm->multi = bluealsa_pcm_multi_create(pcm);
+
 	return 0;
 }
 
@@ -121,6 +128,11 @@ void transport_pcm_free(
 	g_hash_table_unref(pcm->delay_adjustments);
 	g_free(pcm->ba_dbus_path);
 
+	if (pcm->multi != NULL) {
+		bluealsa_pcm_multi_free(pcm->multi);
+		pcm->multi = NULL;
+	}
+
 }
 
 /**
@@ -241,6 +253,10 @@ void ba_transport_pcm_thread_cleanup(struct ba_transport_pcm *pcm) {
 	ba_transport_stop_async(t);
 	pthread_mutex_unlock(&t->bt_fd_mtx);
 
+	/* Stop multi client thread if required. */
+	if (pcm->multi)
+		bluealsa_pcm_multi_reset(pcm->multi);
+
 	/* Release BT socket file descriptor duplicate created either in the
 	 * ba_transport_pcm_start() function or in the IO thread itself. */
 	ba_transport_pcm_bt_release(pcm);
@@ -525,7 +541,7 @@ int ba_transport_pcm_drop(struct ba_transport_pcm *pcm) {
 	pthread_mutex_unlock(&pcm->mutex);
 #endif
 
-	if (io_pcm_flush(pcm) == -1)
+	if (!pcm->multi && io_pcm_flush(pcm) == -1)
 		return -1;
 
 	int rv = ba_transport_pcm_signal_send(pcm, BA_TRANSPORT_PCM_SIGNAL_DROP);
@@ -711,7 +727,10 @@ int ba_transport_pcm_get_delay(const struct ba_transport_pcm *pcm) {
 	if (t->profile & BA_TRANSPORT_PROFILE_MASK_SCO)
 		delay += 10;
 
-	return delay;
+	if (pcm->multi)
+		return delay + pcm->multi->delay;
+	else
+		return delay;
 }
 
 int16_t ba_transport_pcm_delay_adjustment_get(

src/ba-transport-pcm.h

@@ -146,6 +146,9 @@ struct ba_transport_pcm {
 	char *ba_dbus_path;
 	bool ba_dbus_exported;
 
+	/* Multi-client stream support */
+	struct bluealsa_pcm_multi *multi;
+
 };
 
 int transport_pcm_init(