延遲不適用於 Linux 上的 PulseAudio

我有兩個揚聲器。第一個連接到 PCI 卡，第二個通過藍牙連接。聲音在 PCI 卡上播放得稍早一些，所以我想增加一些延遲。我下載了脈衝音頻 GUI，我有這個：

如您所見，我在“Audio Interne”（PCI 卡）上添加了 2 秒的偏移量。

我檢查了命令pactl list cards，我有這個用於內部卡：

Card #1
       Name: alsa_card.pci-0000_00_1b.0
       Driver: module-alsa-card.c
       Owner Module: 8
       Properties:
               alsa.card = "0"
               alsa.card_name = "HDA Intel PCH"
               alsa.long_card_name = "HDA Intel PCH at 0xf7f10000 irq 27"
               alsa.driver_name = "snd_hda_intel"
               device.bus_path = "pci-0000:00:1b.0"
               sysfs.path = "/devices/pci0000:00/0000:00:1b.0/sound/card0"
               device.bus = "pci"
               device.vendor.id = "8086"
               device.vendor.name = "Intel Corporation"
               device.product.id = "1e20"
               device.product.name = "7 Series/C216 Chipset Family High Definition Audio Controller"
               device.form_factor = "internal"
               device.string = "0"
               device.description = "Audio interne"
               module-udev-detect.discovered = "1"
               device.icon_name = "audio-card-pci"
       Profiles:
               input:analog-stereo: Entrée Stéréo analogique (sinks: 0, sources: 1, priority: 65, available: yes)
               output:analog-stereo: Sortie Stéréo analogique (sinks: 1, sources: 0, priority: 6500, available: yes)
               output:analog-stereo+input:analog-stereo: Duplex stéréo analogique (sinks: 1, sources: 1, priority: 6565, available: yes)
               output:analog-surround-21: Sortie Surround analogique 2.1 (sinks: 1, sources: 0, priority: 1300, available: yes)
               output:analog-surround-21+input:analog-stereo: Sortie Surround analogique 2.1 + Entrée Stéréo analogique (sinks: 1, sources: 1, priority: 1365, available: yes)
               output:analog-surround-40: Sortie Surround analogique 4.0 (sinks: 1, sources: 0, priority: 1200, available: yes)
               output:analog-surround-40+input:analog-stereo: Sortie Surround analogique 4.0 + Entrée Stéréo analogique (sinks: 1, sources: 1, priority: 1265, available: yes)
               output:analog-surround-41: Sortie Surround analogique 4.1 (sinks: 1, sources: 0, priority: 1300, available: yes)
               output:analog-surround-41+input:analog-stereo: Sortie Surround analogique 4.1 + Entrée Stéréo analogique (sinks: 1, sources: 1, priority: 1365, available: yes)
               output:analog-surround-50: Sortie Surround analogique 5.0 (sinks: 1, sources: 0, priority: 1200, available: yes)
               output:analog-surround-50+input:analog-stereo: Sortie Surround analogique 5.0 + Entrée Stéréo analogique (sinks: 1, sources: 1, priority: 1265, available: yes)
               output:analog-surround-51: Sortie Surround analogique 5.1 (sinks: 1, sources: 0, priority: 1300, available: yes)
               output:analog-surround-51+input:analog-stereo: Sortie Surround analogique 5.1 + Entrée Stéréo analogique (sinks: 1, sources: 1, priority: 1365, available: yes)
               output:iec958-stereo: Sortie Stéréo numérique (IEC958) (sinks: 1, sources: 0, priority: 5500, available: yes)
               output:iec958-stereo+input:analog-stereo: Sortie Stéréo numérique (IEC958) + Entrée Stéréo analogique (sinks: 1, sources: 1, priority: 5565, available: yes)
               off: Éteint (sinks: 0, sources: 0, priority: 0, available: yes)
       Active Profile: output:analog-stereo
       Ports:
               analog-input-front-mic: Microphone avant (priority: 8500, latency offset: 0 usec, available)
                       Properties:
                               device.icon_name = "audio-input-microphone"
                       Part of profile(s): input:analog-stereo, output:analog-stereo+input:analog-stereo, output:analog-surround-21+input:analog-stereo, output:analog-surround-40+input:analog-stereo, output:analog-surround-41+input:analo
g-stereo, output:analog-surround-50+input:analog-stereo, output:analog-surround-51+input:analog-stereo, output:iec958-stereo+input:analog-stereo
               analog-input-rear-mic: Microphone arrière (priority: 8200, latency offset: 0 usec, not available)
                       Properties:
                               device.icon_name = "audio-input-microphone"
                       Part of profile(s): input:analog-stereo, output:analog-stereo+input:analog-stereo, output:analog-surround-21+input:analog-stereo, output:analog-surround-40+input:analog-stereo, output:analog-surround-41+input:analo
g-stereo, output:analog-surround-50+input:analog-stereo, output:analog-surround-51+input:analog-stereo, output:iec958-stereo+input:analog-stereo
               analog-input-linein: Entrée ligne (priority: 8100, latency offset: 0 usec, available)
                       Part of profile(s): input:analog-stereo, output:analog-stereo+input:analog-stereo, output:analog-surround-21+input:analog-stereo, output:analog-surround-40+input:analog-stereo, output:analog-surround-41+input:analo
g-stereo, output:analog-surround-50+input:analog-stereo, output:analog-surround-51+input:analog-stereo, output:iec958-stereo+input:analog-stereo
               analog-output-lineout: Sortie ligne (priority: 9900, latency offset: 2000000 usec, available)
                       Part of profile(s): output:analog-stereo, output:analog-stereo+input:analog-stereo, output:analog-surround-21, output:analog-surround-21+input:analog-stereo, output:analog-surround-40, output:analog-surround-40+inp
ut:analog-stereo, output:analog-surround-41, output:analog-surround-41+input:analog-stereo, output:analog-surround-50, output:analog-surround-50+input:analog-stereo, output:analog-surround-51, output:analog-surround-51+input:analog-stereo
               analog-output-headphones: Casque audio (priority: 9000, latency offset: 2000000 usec, not available)
                       Properties:
                               device.icon_name = "audio-headphones"
                       Part of profile(s): output:analog-stereo, output:analog-stereo+input:analog-stereo
               iec958-stereo-output: Sortie numérique (S/PDIF) (priority: 0, latency offset: 0 usec)
                       Part of profile(s): output:iec958-stereo, output:iec958-stereo+input:analog-stereo

我試著去做pactl play-sample bell.ogg alsa_output.pci-0000_00_1b.0.analog-stereo。它似乎總是瞬間的。即使我播放音樂，我設置的延遲似乎也沒有改變任何東西。

我能做些什麼？

編輯

隨著pactl list sinks，我看到這個：

Latency: 2039815 usec, configured 40000 usec 

所以似乎延遲設置正確，但是當我播放聲音時它似乎是瞬時的。我想應該有延遲。有什麼我不明白的嗎？

我猜您的螢幕截圖中的延遲偏移只是 Pulsaudio 計算給定採樣頻率的緩衝大小的時間，並嘗試使用 ALSA 安排這些參數。更改那裡的延遲偏移量而不顯示效果可能只是 ALSA 驅動程序不支持多種緩衝區大小。

要獲得額外的緩衝區，您可以添加一個空接收器來使用module-looppack latency_msec，如下所示：

pactl load-module module-null-sink sink_name=delayed
pactl load-module module-loopback latency_msec=2000 source=delayed.monitor sink=alsa_output.pci-0000_00_1b.0.analog-stereo

然後你必須將 null sink 與你的藍牙音頻結合起來。

在沒有module-combine-sink 的情況下測試這個簡單的設置時，我遇到了預期的巨大延遲，如下所示：

paplay someaudio.ext --device delayed

引用自：https://unix.stackexchange.com/questions/492716