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 ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user