To visualize sound you need a sound stream to analyze. Device uses ALSA. Here is the issue: default output device does not provide capture interface, only playback one.
Here are some notes on that:
Press "play" button:
# aplay -l | grep -B1 Subdevices
card 0: sonysoccard [sony-soc-card], device 0: cxd3778gf-hires-out DAI_CXD3778GF_DAC-0 []
Subdevices: 1/1
--
card 0: sonysoccard [sony-soc-card], device 1: cxd3778gf-standard DAI_CXD3778GF_STD-1 []
Subdevices: 1/1
--
card 0: sonysoccard [sony-soc-card], device 2: dsdenc DAI_CXD3778GF_ICX-2 []
Subdevices: 1/1
--
card 0: sonysoccard [sony-soc-card], device 3: cxd3778gf-dsd-out DAI_CXD3778GF_ICX-3 []
Subdevices: 1/1
--
card 0: sonysoccard [sony-soc-card], device 4: cxd3778gf-icx-lowpower DAI_CXD3778GF_ICX-4 []
Subdevices: 0/1 <---- here it is
--
card 0: sonysoccard [sony-soc-card], device 5: cxd3778gf-icx-lowpower_test DAI_CXD3778GF_ICX-5 []
Subdevices: 1/1# aplay -D hw:0,4 /contents/1.wav --dump-hw-params
Playing WAVE '/contents/1.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
HW Params of device "hw:0,4":
--------------------
ACCESS: RW_INTERLEAVED
FORMAT: S16_LE S32_LE DSD_U8 DSD_U16_LE
SUBFORMAT: STD
SAMPLE_BITS: [8 32]
FRAME_BITS: [16 64]
CHANNELS: 2
RATE: [8000 384000]
PERIOD_TIME: [1000 1920000]
PERIOD_SIZE: [384 15360]
PERIOD_BYTES: [3072 30720]
PERIODS: [8 1024]
BUFFER_TIME: [8000 131072000]
BUFFER_SIZE: [3072 1048576]
BUFFER_BYTES: [6144 2097152]
TICK_TIME: ALLPatch and build snd_aloop kernel module:
CONFIG_SND_ALOOP=m
--- sound/drivers/aloop.c 2018-07-18 10:30:55.000000000 +0300
+++ ../linux/sound/drivers/aloop.c 2024-09-30 10:32:54.270468455 +0300
@@ -426,18 +426,21 @@
.info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
SNDRV_PCM_INFO_RESUME),
- .formats = SNDRV_PCM_FMTBIT_S32_LE,
+ .formats = (SNDRV_PCM_FMTBIT_S16_LE
+ | SNDRV_PCM_FMTBIT_S32_LE
+ | SNDRV_PCM_FMTBIT_DSD_U8
+ | SNDRV_PCM_FMTBIT_DSD_U16_LE),
#ifndef CONFIG_SND_ALOOP_RATE_48K_SERIES_ONLY_MODE
.rates = SNDRV_PCM_RATE_44100 |
- SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000,
+ SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000 | SNDRV_PCM_RATE_176400,
.rate_min = 44100,
#else
- .rates = SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_96000,
+ .rates = SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_96000 | SNDRV_PCM_RATE_176400,
.rate_min = 48000,
#endif
- .rate_max = 96000,
- .channels_min = 1,
- .channels_max = 32,
+ .rate_max = 176400,
+ .channels_min = 2,
+ .channels_max = 2,
.buffer_bytes_max = 2 * 1024 * 1024,
.period_bytes_min = 64,
/* note check overflow in frac_pos() using pcm_rate_shift before
# pc
adb push sound/drivers/snd-aloop.ko /system/vendor/unknown321/
# device
insmod /system/vendor/unknown321/snd-aloop.ko/etc/asound.conf (device):
pcm.snd_card { # my usual sound card
type hw
card 0
# device 4
}
ctl.!default { # default control; alsamixer and such will use this
type hw
card 0
}
# software mixer for sound card
pcm.dmixer {
type dmix
ipc_key 1024
ipc_perm 0666 # allow other users
slave.pcm "snd_card"
slave {
period_time 0
period_size 1024
buffer_size 4096
channels 2 # must match bindings
}
bindings {
0 0
1 1
}
}
# software mixer for loopback device
pcm.dmixerloop {
type dmix
ipc_key 2048
ipc_perm 0666 # allow other users
slave.pcm "hw:Loopback,0,0"
slave {
period_time 0
period_size 1024
buffer_size 4096
channels 2 # must match bindings
}
bindings {
0 0
1 1
}
}
# allows multiple programs to capture simultaneously
pcm.dsnooper {
type dsnoop
ipc_key 2048
ipc_perm 0666
slave.pcm "snd_card"
slave
{
period_time 0
period_size 1024
buffer_size 4096
channels 2
}
bindings {
0 0
1 1
}
}
pcm.!default {
type asym
playback.pcm "out"
capture.pcm "dsnooper"
}
# Multi, splitting onto usual card and loopback
pcm.out {
type plug
slave.pcm {
type multi
slaves {
a { channels 2 pcm "dmixer" }
b { channels 2 pcm "dmixerloop" }
}
bindings {
0 { slave a channel 0 }
1 { slave a channel 1 }
2 { slave b channel 0 }
3 { slave b channel 1 }
}
}
ttable [
[ 1 0 1 0 ] # left -> a.left, b.left
[ 0 1 0 1 ] # right -> a.right, b.right
]
}
# aplay /contents/1.wav --dump-hw-params
Playing WAVE '/contents/1.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
HW Params of device "out":
--------------------
ACCESS: MMAP_INTERLEAVED MMAP_NONINTERLEAVED MMAP_COMPLEX RW_INTERLEAVED RW_NONINTERLEAVED
FORMAT: S8 U8 S16_LE S16_BE U16_LE U16_BE S24_LE S24_BE U24_LE U24_BE S32_LE S32_BE U32_LE U32_BE FLOAT_LE FLOAT_BE FLOAT64_LE FLOAT64_BE MU_LAW A_LAW IMA_ADPCM S24_3LE S24_3BE U24_3LE U24_3BE S20_3LE S20_3BE U20_3LE U20_3BE S18_3LE S18_3BE U18_3LE U18_3BE
SUBFORMAT: STD
SAMPLE_BITS: [4 64]
FRAME_BITS: [4 640000]
CHANNELS: [1 10000]
RATE: [4000 4294967295)
PERIOD_TIME: (21333 21334)
PERIOD_SIZE: (85 91628833)
PERIOD_BYTES: (42 4294967295)
PERIODS: (0 4311811)
BUFFER_TIME: [1 4294967295]
BUFFER_SIZE: [170 366503875]
BUFFER_BYTES: [85 4294967295]
TICK_TIME: ALL
--------------------
# aplay -l | grep -B1 Subdevices
card 0: sonysoccard [sony-soc-card], device 0: cxd3778gf-hires-out DAI_CXD3778GF_DAC-0 []
Subdevices: 0/1 <-------------
--
card 0: sonysoccard [sony-soc-card], device 1: cxd3778gf-standard DAI_CXD3778GF_STD-1 []
Subdevices: 1/1
--
card 0: sonysoccard [sony-soc-card], device 2: dsdenc DAI_CXD3778GF_ICX-2 []
Subdevices: 1/1
--
card 0: sonysoccard [sony-soc-card], device 3: cxd3778gf-dsd-out DAI_CXD3778GF_ICX-3 []
Subdevices: 1/1
--
card 0: sonysoccard [sony-soc-card], device 4: cxd3778gf-icx-lowpower DAI_CXD3778GF_ICX-4 []
Subdevices: 1/1
--
card 0: sonysoccard [sony-soc-card], device 5: cxd3778gf-icx-lowpower_test DAI_CXD3778GF_ICX-5 []
Subdevices: 1/1
--
card 1: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]
Subdevices: 7/8 <-------------
--
card 1: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM]
Subdevices: 8/8cava config:
[input]
method = alsa
source = hw:Loopback,1
[output]
method = rawcava spills bytes onto screen = it works... for aplay
/system/vendor/sony/lib/libaudiohal-adleralsa.so, look for hw:0,4, replace with hw:1,0
chmod 0755 /system/vendor/sony/lib/libaudiohal-adleralsa.so
chown root:shell /system/vendor/sony/lib/libaudiohal-adleralsa.soNow music player plays music through loopback device, so..?
# aplay -l | grep -B1 Subdevices
card 0: sonysoccard [sony-soc-card], device 0: cxd3778gf-hires-out DAI_CXD3778GF_DAC-0 []
Subdevices: 1/1
--
card 0: sonysoccard [sony-soc-card], device 1: cxd3778gf-standard DAI_CXD3778GF_STD-1 []
Subdevices: 1/1
--
card 0: sonysoccard [sony-soc-card], device 2: dsdenc DAI_CXD3778GF_ICX-2 []
Subdevices: 1/1
--
card 0: sonysoccard [sony-soc-card], device 3: cxd3778gf-dsd-out DAI_CXD3778GF_ICX-3 []
Subdevices: 1/1
card 0: sonysoccard [sony-soc-card], device 4: cxd3778gf-icx-lowpower DAI_CXD3778GF_ICX-4 []
Subdevices: 1/1 <---- :(
--
card 0: sonysoccard [sony-soc-card], device 5: cxd3778gf-icx-lowpower_test DAI_CXD3778GF_ICX-5 []
Subdevices: 1/1
--
card 1: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]
Subdevices: 7/8 <---- ok
--
card 1: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM]
Subdevices: 8/8libaudiohal uses device directly bypassing asound.conf?