脉冲音频识别SPDIF输出为单声道而不是立体声。

Question

在一个带有archlinux的Cubie载重臂板上，脉冲音频创建了一个单声道接收器，而不是一个立体声/2个通道：

Card #1
    Name: alsa_card.platform-sound
    Driver: module-alsa-card.c
    Owner Module: 22
    Properties:
        alsa.card = "1"
        alsa.card_name = "On-board SPDIF"
        alsa.long_card_name = "On-board SPDIF"
        alsa.driver_name = "snd_soc_simple_card"
        device.bus_path = "platform-sound"
        sysfs.path = "/devices/platform/sound/sound/card1"
        device.form_factor = "internal"
        device.string = "1"
        device.description = "Built-in Audio"
        module-udev-detect.discovered = "1"
        device.icon_name = "audio-card"
    Profiles:
        output:analog-mono: Analog Mono Output (sinks: 1, sources: 0, priority: 700, available: yes)
        off: Off (sinks: 0, sources: 0, priority: 0, available: yes)
    Active Profile: output:analog-mono
    Ports:
        analog-output: Analog Output (priority: 9900, latency offset: 0 usec)
            Part of profile(s): output:analog-mono

直接使用Alsa按预期工作，那么是什么导致了这个问题呢？

Answer 1

诀窍是通过注释掉load-module module-udev-autodetect和load-module module-autodetect并在default.pa配置文件中手动设置声卡：load-module module-alsa-sink device=default:CARD=SPDIF channels=2 rate=44100 channel_map=left,right来避免设备自动检测。