Eu tenho um USB C-Media soundcard instalado no meu Raspberry Pi: Bus 001 Device 004: ID 0d8c:0008 C-Media Electronics, Inc.
. É um cabo USB com uma extremidade XLR do outro lado, ao qual eu tenho um microfone XLR (um Sennheiser MD 427, se alguém estiver interessado) conectado:
Conectando-o ao meu Mac, posso aumentar o volume de gravação (ele diz "configurações para o dispositivo selecionado" e "volume de entrada" em alemão) e recebo uma gravação razoavelmente correta (na verdade, é uma gravação estéreo, mas isso mostra o volume nível):
Agora, o mesmo no Linux parece bem diferente. O dispositivo é reconhecido como ok, snd_usb_audio
está carregado e alsamixer
mostra o novo dispositivo de gravação e permite aumentar o "volume da gravação" até o fim:
No entanto, o volume do que posso gravar usando # AUDIODEV=hw:1 rec tmp.wav
é péssimo:
Agora, existe uma maneira de alterar as configurações do módulo do kernel para que eu possa "aumentar o volume da gravação" mais do que me é apresentado? Ou talvez outras configurações que eu tenha esquecido?
Eu posso "suavizar" a gravação usando # AUDIODEV=hw:1 rec tmp.wav gain 20
, mas isso também aumenta o ruído e ainda está abaixo do que o Mac grava.
Antes de você perguntar:
# arecord -L
null
Discard all samples (playback) or generate zero samples (capture)
default:CARD=Device
C-Media USB Audio Device, USB Audio
Default Audio Device
sysdefault:CARD=Device
C-Media USB Audio Device, USB Audio
Default Audio Device
front:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
Front speakers
surround21:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
4.0 Surround output to Front and Rear speakers
surround41:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
IEC958 (S/PDIF) Digital Audio Output
dmix:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
Direct sample mixing device
dsnoop:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
Direct sample snooping device
hw:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
Direct hardware device without any conversions
plughw:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
Hardware device with all software conversions
#
# lsusb
Bus 001 Device 005: ID 0d8c:0008 C-Media Electronics, Inc.
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
#
# arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: Device [C-Media USB Audio Device], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0
#
# amixer -c 1 scontrols
Simple mixer control 'PCM',0
Simple mixer control 'Mic',0
Simple mixer control 'Auto Gain Control',0
#
# uname -ra
Linux xxx 4.4.16+ #899 Thu Jul 28 12:36:19 BST 2016 armv6l GNU/Linux
#
# aplay -l -L
null
Discard all samples (playback) or generate zero samples (capture)
default:CARD=ALSA
bcm2835 ALSA, bcm2835 ALSA
Default Audio Device
sysdefault:CARD=ALSA
bcm2835 ALSA, bcm2835 ALSA
Default Audio Device
dmix:CARD=ALSA,DEV=0
bcm2835 ALSA, bcm2835 ALSA
Direct sample mixing device
dmix:CARD=ALSA,DEV=1
bcm2835 ALSA, bcm2835 IEC958/HDMI
Direct sample mixing device
dsnoop:CARD=ALSA,DEV=0
bcm2835 ALSA, bcm2835 ALSA
Direct sample snooping device
dsnoop:CARD=ALSA,DEV=1
bcm2835 ALSA, bcm2835 IEC958/HDMI
Direct sample snooping device
hw:CARD=ALSA,DEV=0
bcm2835 ALSA, bcm2835 ALSA
Direct hardware device without any conversions
hw:CARD=ALSA,DEV=1
bcm2835 ALSA, bcm2835 IEC958/HDMI
Direct hardware device without any conversions
plughw:CARD=ALSA,DEV=0
bcm2835 ALSA, bcm2835 ALSA
Hardware device with all software conversions
plughw:CARD=ALSA,DEV=1
bcm2835 ALSA, bcm2835 IEC958/HDMI
Hardware device with all software conversions
default:CARD=Device
C-Media USB Audio Device, USB Audio
Default Audio Device
sysdefault:CARD=Device
C-Media USB Audio Device, USB Audio
Default Audio Device
front:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
Front speakers
surround21:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
4.0 Surround output to Front and Rear speakers
surround41:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
IEC958 (S/PDIF) Digital Audio Output
dmix:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
Direct sample mixing device
dsnoop:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
Direct sample snooping device
hw:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
Direct hardware device without any conversions
plughw:CARD=Device,DEV=0
C-Media USB Audio Device, USB Audio
Hardware device with all software conversions
**** List of PLAYBACK Hardware Devices ****
card 0: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]
Subdevices: 8/8
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
Subdevice #4: subdevice #4
Subdevice #5: subdevice #5
Subdevice #6: subdevice #6
Subdevice #7: subdevice #7
card 0: ALSA [bcm2835 ALSA], device 1: bcm2835 ALSA [bcm2835 IEC958/HDMI]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: Device [C-Media USB Audio Device], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0
#
# lsusb -v -d 0d8c:0008
Bus 001 Device 004: ID 0d8c:0008 C-Media Electronics, Inc.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x0d8c C-Media Electronics, Inc.
idProduct 0x0008
bcdDevice 1.00
iManufacturer 0
iProduct 1 C-Media USB Audio Device
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 224
bNumInterfaces 4
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xa0
(Bus Powered)
Remote Wakeup
MaxPower 100mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 1 Control Device
bInterfaceProtocol 0
iInterface 0
AudioControl Interface Descriptor:
bLength 10
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdADC 1.00
wTotalLength 71
bInCollection 2
baInterfaceNr( 0) 1
baInterfaceNr( 1) 2
AudioControl Interface Descriptor:
bLength 12
bDescriptorType 36
bDescriptorSubtype 2 (INPUT_TERMINAL)
bTerminalID 1
wTerminalType 0x0101 USB Streaming
bAssocTerminal 0
bNrChannels 2
wChannelConfig 0x0003
Left Front (L)
Right Front (R)
iChannelNames 0
iTerminal 0
AudioControl Interface Descriptor:
bLength 12
bDescriptorType 36
bDescriptorSubtype 2 (INPUT_TERMINAL)
bTerminalID 2
wTerminalType 0x0201 Microphone
bAssocTerminal 0
bNrChannels 1
wChannelConfig 0x0001
Left Front (L)
iChannelNames 0
iTerminal 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 6
wTerminalType 0x0301 Speaker
bAssocTerminal 0
bSourceID 9
iTerminal 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 7
wTerminalType 0x0101 USB Streaming
bAssocTerminal 0
bSourceID 10
iTerminal 0
AudioControl Interface Descriptor:
bLength 10
bDescriptorType 36
bDescriptorSubtype 6 (FEATURE_UNIT)
bUnitID 9
bSourceID 1
bControlSize 1
bmaControls( 0) 0x01
Mute Control
bmaControls( 1) 0x02
Volume Control
bmaControls( 2) 0x02
Volume Control
iFeature 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 6 (FEATURE_UNIT)
bUnitID 10
bSourceID 2
bControlSize 1
bmaControls( 0) 0x43
Mute Control
Volume Control
Automatic Gain Control
bmaControls( 1) 0x00
iFeature 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
AudioStreaming Interface Descriptor:
bLength 7
bDescriptorType 36
bDescriptorSubtype 1 (AS_GENERAL)
bTerminalLink 1
bDelay 1 frames
wFormatTag 1 PCM
AudioStreaming Interface Descriptor:
bLength 14
bDescriptorType 36
bDescriptorSubtype 2 (FORMAT_TYPE)
bFormatType 1 (FORMAT_TYPE_I)
bNrChannels 2
bSubframeSize 2
bBitResolution 16
bSamFreqType 2 Discrete
tSamFreq[ 0] 48000
tSamFreq[ 1] 44100
Endpoint Descriptor:
bLength 9
bDescriptorType 5
bEndpointAddress 0x01 EP 1 OUT
bmAttributes 9
Transfer Type Isochronous
Synch Type Adaptive
Usage Type Data
wMaxPacketSize 0x00c8 1x 200 bytes
bInterval 1
bRefresh 0
bSynchAddress 0
AudioControl Endpoint Descriptor:
bLength 7
bDescriptorType 37
bDescriptorSubtype 1 (EP_GENERAL)
bmAttributes 0x01
Sampling Frequency
bLockDelayUnits 1 Milliseconds
wLockDelay 1 Milliseconds
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
AudioStreaming Interface Descriptor:
bLength 7
bDescriptorType 36
bDescriptorSubtype 1 (AS_GENERAL)
bTerminalLink 7
bDelay 1 frames
wFormatTag 1 PCM
AudioStreaming Interface Descriptor:
bLength 14
bDescriptorType 36
bDescriptorSubtype 2 (FORMAT_TYPE)
bFormatType 1 (FORMAT_TYPE_I)
bNrChannels 1
bSubframeSize 2
bBitResolution 16
bSamFreqType 2 Discrete
tSamFreq[ 0] 48000
tSamFreq[ 1] 44100
Endpoint Descriptor:
bLength 9
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x0064 1x 100 bytes
bInterval 1
bRefresh 0
bSynchAddress 0
AudioControl Endpoint Descriptor:
bLength 7
bDescriptorType 37
bDescriptorSubtype 1 (EP_GENERAL)
bmAttributes 0x01
Sampling Frequency
bLockDelayUnits 0 Undefined
wLockDelay 0 Undefined
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 3
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 3 Human Interface Device
bInterfaceSubClass 0 No Subclass
bInterfaceProtocol 0 None
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.00
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 50
Report Descriptors:
** UNAVAILABLE **
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0004 1x 4 bytes
bInterval 32
Device Status: 0x0000
(Bus Powered)
#
ALSA
apenas e pavucontrol
parecem precisar do X11, que não estou executando nesta máquina.
pavucontrol
. Mas você está usando pulseaudio
para inserir um misturador básico no espaço do usuário, certo? (Atualmente, a maioria das distros usa alsa
para controlar o cartão e pulseaudio
interagir com o usuário real.) Mas se você tem certeza de que pulseaudio
não faz parte da sua configuração, sim, pavucontrol
isso não ajudará.
pavucontrol
, a ferramenta de controle do pulseaudio (pode ser necessário instalá-lo). Eu tive um problema muito semelhante no linux