Add support for LC3plus A2DP source and sink

Closes #479

NEWS

@@ -2,6 +2,7 @@ unreleased
 ==========
 
 - optional support for A2DP FastStream codec (music & voice)
+- optional support for A2DP LC3plus codec (music & voice)
 - enable/disable BT profiles/codecs via command line options
 - allow to select BT transport codec with ALSA configuration
 - allow to set PCM volume properties with ALSA configuration

README.md

@@ -53,6 +53,8 @@ Dependencies:
 - [fdk-aac](https://github.com/mstorsjo/fdk-aac) (when AAC support is enabled with `--enable-aac`)
 - [openaptx](https://github.com/Arkq/openaptx) (when apt-X support is enabled with
   `--enable-aptx` and/or `--enable-aptx-hd`)
+- [lc3plus](https://www.iis.fraunhofer.de/en/ff/amm/communication/lc3.html) (when LC3plus support is
+  enabled with `--enable-lc3plus`)
 - [libopenaptx](https://github.com/pali/libopenaptx) (when apt-X support is enabled and
   `--with-libopenaptx` is used)
 - [libldac](https://github.com/EHfive/ldacBT) (when LDAC support is enabled with `--enable-ldac`)

configure.ac

@@ -152,6 +152,17 @@ AM_COND_IF([ENABLE_FASTSTREAM], [
 	AC_DEFINE([ENABLE_FASTSTREAM], [1], [Define to 1 if FastStream is enabled.])
 ])
 
+AC_ARG_ENABLE([lc3plus],
+	[AS_HELP_STRING([--enable-lc3plus], [enable LC3plus support])])
+AM_CONDITIONAL([ENABLE_LC3PLUS], [test "x$enable_lc3plus" = "xyes"])
+AM_COND_IF([ENABLE_LC3PLUS], [
+	AC_CHECK_HEADERS([lc3.h],
+		[], [AC_MSG_ERROR([LC3plus header file not found])])
+	AC_CHECK_LIB([LC3plus], [lc3plus_version],
+		[AC_SUBST([LC3PLUS_LIBS], [-lLC3plus])], [AC_MSG_ERROR([LC3plus library not found])])
+	AC_DEFINE([ENABLE_LC3PLUS], [1], [Define to 1 if LC3plus is enabled.])
+])
+
 AC_ARG_ENABLE([ldac],
 	[AS_HELP_STRING([--enable-ldac], [enable LDAC support])])
 AM_CONDITIONAL([ENABLE_LDAC], [test "x$enable_ldac" = "xyes"])

doc/bluealsa.8.rst

@@ -173,6 +173,10 @@ OPTIONS
     will be used.
     Used AAC configuration depends on a remote Bluetooth device capabilities.
 
+--lc3plus-bitrate=BPS
+    Set LC3plus encoder bit rate for constant bit rate mode (CBR) as *BPS*.
+    Default value is **264000** bits per second.
+
 --ldac-abr
     Enables LDAC adaptive bit rate, which will dynamically adjust encoder quality
     based on the connection stability.

src/Makefile.am

@@ -62,6 +62,11 @@ bluealsa_SOURCES += \
 	a2dp-faststream.c
 endif
 
+if ENABLE_LC3PLUS
+bluealsa_SOURCES += \
+	a2dp-lc3plus.c
+endif
+
 if ENABLE_LDAC
 bluealsa_SOURCES += \
 	a2dp-ldac.c
@@ -111,6 +116,7 @@ LDADD = \
 	@BLUEZ_LIBS@ \
 	@GIO2_LIBS@ \
 	@GLIB2_LIBS@ \
+	@LC3PLUS_LIBS@ \
 	@LDAC_ABR_LIBS@ \
 	@LDAC_DEC_LIBS@ \
 	@LDAC_ENC_LIBS@ \

src/a2dp-aac.c

@@ -367,15 +367,15 @@ static void *a2dp_aac_enc_thread(struct ba_transport_thread *th) {
 						goto fail;
 					}
 
-					/* account written payload only */
+					/* resend RTP header */
 					len -= RTP_HEADER_LEN;
 
-					/* break if the last part of the payload has been written */
+					/* break if there is no more payload data */
 					if ((payload_len -= len) == 0)
 						break;
 
-					/* move rest of data to the beginning of the payload */
-					debug("Payload fragmentation: extra %zd bytes", payload_len);
+					/* move the rest of data to the beginning of payload */
+					debug("AAC payload fragmentation: extra %zu bytes", payload_len);
 					memmove(rtp_payload, rtp_payload + len, payload_len);
 
 				}