Hi
I am using the snd-aloop alsa driver and i wanna first inject one stream
using ffmpeg then record it into a file still using ffmpeg.
The injection from the pcm stream is done as follow to the alsa Loopback
devices :
/usr/local/bin/ffmpeg -f s16le -acodec pcm_s16le -i tcp://localhost:4001
-f alsa hw:1
Then to record from the Loopback device :
/usr/local/bin/ffmpeg -f alsa -acodec pcm_s16le hw:1
My problem is to define which input to use for the -i parameter. Indeed,
between the hw:1,0 or hw:1, ... and so on, this is not very clear.
Can i use hw:1, hw:1,0, default, or something else ?
Using my config, does anybody can help to define the right alsa device
for ffmpeg.
Here is a detail of my settings :
root@amahealth-pc:~# arecord -l
**** Liste des Périphériques Matériels CAPTURE ****
carte 0: PCH [HDA Intel PCH], périphérique 0: ALC282 Analog [ALC282 Analog]
Sous-périphériques: 0/1
Sous-périphérique #0: subdevice #0
carte 1: Loopback [Loopback], périphérique 0: Loopback PCM [Loopback PCM]
Sous-périphériques: 0/1
Sous-périphérique #0: subdevice #0
carte 1: Loopback [Loopback], périphérique 1: Loopback PCM [Loopback PCM]
Sous-périphériques: 1/1
Sous-périphérique #0: subdevice #0
root@amahealth-pc:~# arecord -L
null
Discard all samples (playback) or generate zero samples (capture)
pulse
PulseAudio Sound Server
default
Playback/recording through the PulseAudio sound server
sysdefault:CARD=PCH
HDA Intel PCH, ALC282 Analog
Default Audio Device
front:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
Front speakers
surround40:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
4.0 Surround output to Front and Rear speakers
surround41:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
dmix:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
Direct sample mixing device
dsnoop:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
Direct sample snooping device
hw:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
Direct hardware device without any conversions
plughw:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
Hardware device with all software conversions
sysdefault:CARD=Loopback
Loopback, Loopback PCM
Default Audio Device
dmix:CARD=Loopback,DEV=0
Loopback, Loopback PCM
Direct sample mixing device
dmix:CARD=Loopback,DEV=1
Loopback, Loopback PCM
Direct sample mixing device
dsnoop:CARD=Loopback,DEV=0
Loopback, Loopback PCM
Direct sample snooping device
dsnoop:CARD=Loopback,DEV=1
Loopback, Loopback PCM
Direct sample snooping device
hw:CARD=Loopback,DEV=0
Loopback, Loopback PCM
Direct hardware device without any conversions
hw:CARD=Loopback,DEV=1
Loopback, Loopback PCM
Direct hardware device without any conversions
plughw:CARD=Loopback,DEV=0
Loopback, Loopback PCM
Hardware device with all software conversions
plughw:CARD=Loopback,DEV=1
Loopback, Loopback PCM
Hardware device with all software conversions
root@amahealth-pc:~# aplay -L
null
Discard all samples (playback) or generate zero samples (capture)
pulse
PulseAudio Sound Server
default
Playback/recording through the PulseAudio sound server
sysdefault:CARD=PCH
HDA Intel PCH, ALC282 Analog
Default Audio Device
front:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
Front speakers
surround40:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
4.0 Surround output to Front and Rear speakers
surround41:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
hdmi:CARD=PCH,DEV=0
HDA Intel PCH, HDMI 0
HDMI Audio Output
hdmi:CARD=PCH,DEV=1
HDA Intel PCH, HDMI 1
HDMI Audio Output
dmix:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
Direct sample mixing device
dmix:CARD=PCH,DEV=3
HDA Intel PCH, HDMI 0
Direct sample mixing device
dmix:CARD=PCH,DEV=7
HDA Intel PCH, HDMI 1
Direct sample mixing device
dsnoop:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
Direct sample snooping device
dsnoop:CARD=PCH,DEV=3
HDA Intel PCH, HDMI 0
Direct sample snooping device
dsnoop:CARD=PCH,DEV=7
HDA Intel PCH, HDMI 1
Direct sample snooping device
hw:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
Direct hardware device without any conversions
hw:CARD=PCH,DEV=3
HDA Intel PCH, HDMI 0
Direct hardware device without any conversions
hw:CARD=PCH,DEV=7
HDA Intel PCH, HDMI 1
Direct hardware device without any conversions
plughw:CARD=PCH,DEV=0
HDA Intel PCH, ALC282 Analog
Hardware device with all software conversions
plughw:CARD=PCH,DEV=3
HDA Intel PCH, HDMI 0
Hardware device with all software conversions
plughw:CARD=PCH,DEV=7
HDA Intel PCH, HDMI 1
Hardware device with all software conversions
sysdefault:CARD=Loopback
Loopback, Loopback PCM
Default Audio Device
dmix:CARD=Loopback,DEV=0
Loopback, Loopback PCM
Direct sample mixing device
dmix:CARD=Loopback,DEV=1
Loopback, Loopback PCM
Direct sample mixing device
dsnoop:CARD=Loopback,DEV=0
Loopback, Loopback PCM
Direct sample snooping device
dsnoop:CARD=Loopback,DEV=1
Loopback, Loopback PCM
Direct sample snooping device
hw:CARD=Loopback,DEV=0
Loopback, Loopback PCM
Direct hardware device without any conversions
hw:CARD=Loopback,DEV=1
Loopback, Loopback PCM
Direct hardware device without any conversions
plughw:CARD=Loopback,DEV=0
Loopback, Loopback PCM
Hardware device with all software conversions
plughw:CARD=Loopback,DEV=1
Loopback, Loopback PCM
Hardware device with all software conversions
root@amahealth-pc:~# aplay -l
**** Liste des Périphériques Matériels PLAYBACK ****
carte 0: PCH [HDA Intel PCH], périphérique 0: ALC282 Analog [ALC282 Analog]
Sous-périphériques: 1/1
Sous-périphérique #0: subdevice #0
carte 0: PCH [HDA Intel PCH], périphérique 3: HDMI 0 [HDMI 0]
Sous-périphériques: 1/1
Sous-périphérique #0: subdevice #0
carte 0: PCH [HDA Intel PCH], périphérique 7: HDMI 1 [HDMI 1]
Sous-périphériques: 1/1
Sous-périphérique #0: subdevice #0
carte 1: Loopback [Loopback], périphérique 0: Loopback PCM [Loopback PCM]
Sous-périphériques: 1/1
Sous-périphérique #0: subdevice #0
carte 1: Loopback [Loopback], périphérique 1: Loopback PCM [Loopback PCM]
Sous-périphériques: 1/1
Sous-périphérique #0: subdevice #0
root@amahealth-pc:~# cat /proc/asound/modules
0 snd_hda_intel
1 snd_aloop
root@amahealth-pc:~# cat /proc/asound/
card0/ card1/ cards devices hwdep Loopback/ modules
PCH/ pcm seq/ timers version
root@amahealth-pc:~# cat /proc/asound/devices
1: : sequencer
2: [ 1- 1]: digital audio playback
3: [ 1- 1]: digital audio capture
4: [ 1- 0]: digital audio playback
5: [ 1- 0]: digital audio capture
6: [ 1] : control
7: [ 0- 7]: digital audio playback
8: [ 0- 3]: digital audio playback
9: [ 0- 0]: digital audio playback
10: [ 0- 0]: digital audio capture
11: [ 0- 3]: hardware dependent
12: [ 0- 0]: hardware dependent
13: [ 0] : control
33: : timer
root@amahealth-pc:~# cat /proc/asound/pcm
00-00: ALC282 Analog : ALC282 Analog : playback 1 : capture 1
00-03: HDMI 0 : HDMI 0 : playback 1
00-07: HDMI 1 : HDMI 1 : playback 1
01-00: Loopback PCM : Loopback PCM : playback 1 : capture 1
01-01: Loopback PCM : Loopback PCM : playback 1 : capture 1
root@amahealth-pc:~# cat /proc/asound/cards
0 [PCH ]: HDA-Intel - HDA Intel PCH
HDA Intel PCH at 0xe0630000 irq 44
1 [Loopback ]: Loopback - Loopback
Loopback 1
--
Regards
Thierry GAYET
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