Quiero transmitir audio desde mi equipo Linux a un dispositivo Android, con el menor retraso posible, así que pensé en usar PulseAudio con module-opensl-sink(encontradoaquí). Ino quieroreemplace AudioFlinger con PA, porque quiero usar su API de efectos.
Me las arreglé para compilar PulseAudio usando el NDK de Android de Google de alguna manera, pero cada vez que intento iniciarlo, arroja un error, sin importar qué módulo intente cargar.
$ ./pulseaudio -C --loglevel=4
W: [pulseaudio] caps.c: Normally all extra capabilities would be dropped now, but that's impossible because PulseAudio was built without capabilities support.
I: [pulseaudio] main.c: setrlimit(RLIMIT_RTPRIO, (9, 9)) failed: Operation not permitted
D: [pulseaudio] core-util.c: setpriority() worked.
I: [pulseaudio] core-util.c: Successfully gained nice level -11.
I: [pulseaudio] main.c: This is PulseAudio 5.0-121-g38c5d-dirty
D: [pulseaudio] main.c: Compilation host: arm-unknown-linux-androideabi
D: [pulseaudio] main.c: Compilation CFLAGS: -mfpu=neon -mfloat-abi=softfp -Wall -W -Wextra -pipe -Wno-long-long -Wno-overlength-strings -Wunsafe-loop-optimizations -Wundef -Wformat=2 -Wlogical-op -Wsign-compare -Wformat-security -Wmissing-include-dirs -Wformat-nonliteral -Wpointer-arith -Winit-self -Wdeclaration-after-statement -Wfloat-equal -Wmissing-prototypes -Wredundant-decls -Wmissing-declarations -Wmissing-noreturn -Wshadow -Wendif-labels -Wcast-align -Wstrict-aliasing -Wwrite-strings -Wno-unused-parameter -ffast-math -fno-common -fdiagnostics-show-option
D: [pulseaudio] main.c: Running on host: Linux armv7l 3.4.0-cyanogenmod-g8a32cd7 #1 SMP PREEMPT Sun Jun 8 19:40:15 PDT 2014
D: [pulseaudio] main.c: Found 4 CPUs.
I: [pulseaudio] main.c: Page size is 4096 bytes
D: [pulseaudio] main.c: Compiled with Valgrind support: no
D: [pulseaudio] main.c: Running in valgrind mode: no
D: [pulseaudio] main.c: Running in VM: no
D: [pulseaudio] main.c: Optimized build: no
D: [pulseaudio] main.c: FASTPATH defined, only fast path asserts disabled.
I: [pulseaudio] main.c: Machine ID is localhost.
I: [pulseaudio] main.c: Using runtime directory /data/data/jackpal.androidterm/app_HOME/.config/pulse/localhost-runtime.
I: [pulseaudio] main.c: Using state directory /data/data/jackpal.androidterm/app_HOME/.config/pulse.
I: [pulseaudio] main.c: Using modules directory /data/local/pa/lib/pulse-5.0/modules.
I: [pulseaudio] main.c: Running in system mode: no
I: [pulseaudio] main.c: Fresh high-resolution timers available! Bon appetit!
W: [pulseaudio] core.c: failed to allocate shared memory pool. Falling back to a normal memory pool.
D: [pulseaudio] memblock.c: Using private memory pool with 1024 slots of size 64.0 KiB each, total size is 64.0 MiB, maximum usable slot size is 65496
I: [pulseaudio] cpu-arm.c: CPU flags: V6 V7 VFP EDSP NEON VFPV3
I: [pulseaudio] sconv_neon.c: Initialising ARM NEON optimized conversions.
I: [pulseaudio] mix_neon.c: Initialising ARM NEON optimized mixing functions.
I: [pulseaudio] remap_neon.c: Initialising ARM NEON optimized remappers.
E: [pulseaudio] module.c: Failed to open module "module-cli".
E: [pulseaudio] main.c: Module load failed.
E: [pulseaudio] main.c: Failed to initialize daemon.
I: [pulseaudio] main.c: Daemon terminated.
Configuré PA con estos argumentos:
./configure --prefix="/data/local/pa" --host arm-linux-androideabi --enable-neon-opt --with-sysroot='/data/local/pa' --without-caps --disable-shared --enable-static --disable-avahi --disable-alsa --disable-jack --disable-gconf --disable-esound --disable-openssl --disable-dbus --disable-glib2 --disable-orc --disable-adrian-aec --disable-rpath --enable-static-bins --disable-ipv6 --enable-force-preopen
¿Por qué no puede encontrar estos módulos, incluso si informa el directorio de módulos correcto?
Respuesta1
Un error en PulseAudio provocó que los módulos se construyeran incorrectamente (como bibliotecas estáticas), por lo que no se podían cargar. Reconfigurar sin --disable-shared --enable-static --enable-static-binshacerlo funcionar :)
Respuesta2
Puedes usar mi versión de servidor.https://github.com/twaik/pulseaudio-sles-ndk. Se decide construirlo utilizando el NDK de Android.