Hi, I want to capture the audio stream of my TV with my PCI-E Toslink sound card and play it back on my usb XLR soundcard. The reason why I do that is to use my own music boxes rather than the TV speakers. With toslink + XLR I do not have problems with ground loops etc. I am using the pulseaudio loopback module with its default configuration. The problem is, that the delay between picture and sound is about one second off, and the longer I wait, the more delay it gets (30 seconds and more). It is no usable like this. I tried to play with the latencies of source, sink and the tv delay itself without sucess. I also tried streaming with pacat directly as described here: https://thelinuxexperiment.com/fix-pulseaudio-loopback-delay/ I also tried to change different parameters of the loopback module or the sources/sinks, but that did not help. I never changed any global pulseaudio config to avoid larger configuration issues. The CPU usage of pulseaudio is at 3% with the loopback module Can anyone help me to get rid of this lag? Here are some additional information: Source device: Source #1 State: RUNNING Name: alsa_input.pci-0000_01_00.0.iec958-stereo Description: CM8888 [Oxygen Express] (HDA Controller) Digital Stereo (IEC958) Driver: module-alsa-card.c Sample Specification: s16le 2ch 44100Hz Channel Map: front-left,front-right Owner Module: 7 Mute: no Volume: front-left: 65536 / 100% / 0.00 dB, front-right: 65536 / 100% / 0.00 dB balance 0.00 Base Volume: 65536 / 100% / 0.00 dB Monitor of Sink: n/a Latency: 34402 usec, configured 40000 usec Flags: HARDWARE DECIBEL_VOLUME LATENCY Properties: alsa.resolution_bits = "16" device.api = "alsa" device.class = "sound" alsa.class = "generic" alsa.subclass = "generic-mix" alsa.name = "Generic Digital" alsa.id = "Generic Digital" alsa.subdevice = "0" alsa.subdevice_name = "subdevice #0" alsa.device = "1" alsa.card = "2" alsa.card_name = "HDA C-Media" alsa.long_card_name = "HDA C-Media at 0xfea00000 irq 24" alsa.driver_name = "snd_hda_intel" device.bus_path = "pci-0000:01:00.0" sysfs.path = "/devices/pci0000:00/0000:00:02.1/0000:01:00.0/sound/card2" device.bus = "pci" device.vendor.id = "13f6" device.vendor.name = "C-Media Electronics Inc" device.product.id = "5011" device.product.name = "CM8888 [Oxygen Express] (HDA Controller)" device.string = "iec958:2" device.buffering.buffer_size = "352768" device.buffering.fragment_size = "176384" device.access_mode = "mmap+timer" device.profile.name = "iec958-stereo" device.profile.description = "Digital Stereo (IEC958)" device.description = "CM8888 [Oxygen Express] (HDA Controller) Digital Stereo (IEC958)" alsa.mixer_name = "C-Media Generic" alsa.components = "HDA:13f68828,13f68280,00109900" module-udev-detect.discovered = "1" device.icon_name = "audio-card-pci" Ports: iec958-stereo-input: Digital Input (S/PDIF) (priority: 0) Active Port: iec958-stereo-input Formats: pcm Sink device: Sink #1 State: RUNNING Name: alsa_output.usb-M-AUDIO_M-Track_Hub-00.analog-stereo Description: M-Track Hub Analog Stereo Driver: module-alsa-card.c Sample Specification: s24le 2ch 44100Hz Channel Map: front-left,front-right Owner Module: 8 Mute: no Volume: front-left: 65536 / 100% / 0.00 dB, front-right: 65536 / 100% / 0.00 dB balance 0.00 Base Volume: 65536 / 100% / 0.00 dB Monitor Source: alsa_output.usb-M-AUDIO_M-Track_Hub-00.analog-stereo.monitor Latency: 25099 usec, configured 23220 usec Flags: HARDWARE DECIBEL_VOLUME LATENCY Properties: alsa.resolution_bits = "24" device.api = "alsa" device.class = "sound" alsa.class = "generic" alsa.subclass = "generic-mix" alsa.name = "USB Audio" alsa.id = "USB Audio" alsa.subdevice = "0" alsa.subdevice_name = "subdevice #0" alsa.device = "0" alsa.card = "3" alsa.card_name = "M-Track Hub" alsa.long_card_name = "M-AUDIO M-Track Hub at usb-0000:00:12.0-1.2.4, full speed" alsa.driver_name = "snd_usb_audio" device.bus_path = "pci-0000:00:12.0-usb-0:1.2.4:1.0" sysfs.path = "/devices/pci0000:00/0000:00:12.0/usb1/1-1/1-1.2/1-1.2.4/1-1.2.4:1.0/sound/card3" udev.id = "usb-M-AUDIO_M-Track_Hub-00" device.bus = "usb" device.vendor.id = "0763" device.vendor.name = "M-Audio" device.product.id = "400d" device.product.name = "M-Track Hub" device.serial = "M-AUDIO_M-Track_Hub" device.string = "front:3" device.buffering.buffer_size = "529200" device.buffering.fragment_size = "264600" device.access_mode = "mmap+timer" device.profile.name = "analog-stereo" device.profile.description = "Analog Stereo" device.description = "M-Track Hub Analog Stereo" alsa.mixer_name = "USB Mixer" alsa.components = "USB0763:400d" module-udev-detect.discovered = "1" device.icon_name = "audio-card-usb" Ports: analog-output: Analog Output (priority: 9900) Active Port: analog-output Formats: pcm Regards Nico
