Details
P2: Important Description
Hi,
I have come across this issue in my current project which is Yocto-RPi5 based work that involves a Qt/QML application which is supposed to play audio track using MediaPlayer QML item. I would like to play music through alsa in Linux, not pulseaudio.
speaker-test, gst-launch, and aplay all work, I can hear sound from these commands:
aplay /usr/share/sounds/alsa/Front_Center.wav gst-launch-1.0 audiotestsrc freq=1000 ! audioconvert ! audioresample ! alsasink speaker-test -t wav
gstreamer-plugins-base compiled with alsa option, qtmultimedia compiled with alsa and gstreamer options:
PACKAGECONFIG:append:pn-gstreamer1.0-plugins-base = " alsa" PACKAGECONFIG:append:pn-qtmultimedia = " alsa" PACKAGECONFIG:append:pn-qtmultimedia = " gstreamer" PACKAGECONFIG:remove:pn-qtmultimedia = "pulseaudio" PACKAGECONFIG:remove:pn-qtmultimedia = "ffmpeg"
I have a wm8960 device attached which has following configuration:
# Set default card defaults.pcm.card 2 defaults.ctl.card 2 # Use samplerate for resampling defaults.pcm.rate_converter "samplerate" # Define default PCM for playback and capture pcm.!default { type asym playback.pcm "playback" capture.pcm "capture" } pcm.playback { type plug slave.pcm "dmixed" } pcm.capture { type plug slave.pcm "array" } pcm.dmixed { type dmix slave { pcm "hw:2,0" # Corrected from "hw:wm8960soundcard" rate 48000 # Ensure sample rate matches your hardware period_time 0 period_size 1024 buffer_size 4096 } ipc_key 555555 } pcm.array { type dsnoop slave { pcm "hw:2,0" # Corrected from "hw:wm8960soundcard" channels 2 } ipc_key 666666 }
aplay -l output:
card 0: vc4hdmi0 [vc4-hdmi-0], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0] Subdevices: 1/1 Subdevice #0: subdevice #0 card 1: vc4hdmi1 [vc4-hdmi-1], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0] Subdevices: 1/1 Subdevice #0: subdevice #0 card 2: wm8960soundcard [wm8960-soundcard], device 0: 1f000a0000.i2s-wm8960-hifi wm8960-hifi-0 [1f000a0000.i2s- wm8960-hifi wm8960-hifi-0] Subdevices: 1/1 Subdevice #0: subdevice #0
However, with qtmultimedia I can not seem to have audio for some reason. I suspect that my device is not recognized by qtmultimedia or there is some config I need to do which I am missing.
GST_DEBUG=3 QT_GSTREAMER_AUDIOSINK="alsasink device=hw:2,0" pi_launcher -platform wayland 0:00:12.242944215 475 0x7fff54001240 FIXME decodebin3 gstdecodebin3.c:2015:gst_decodebin_input_re quires_parsebin:<decodebin3-0:sink> parsebin not needed (matches output caps) ! 0:00:12.243285863 475 0x7fff54001240 FIXME decodebin3 gstdecodebin3.c:1298:gst_decodebin_input_un block_streams:<decodebin3-0> Re-use existing input streams if/when possible 0:00:12.243604270 475 0x7fff54001240 FIXME decodebin3 gstdecodebin3.c:948:check_all_input_streams _for_eos:<multiqueue0:sink_0> Remove input stream 0:00:12.247219252 475 0x7fff540012a0 WARN alsa pcm_hw.c:1801:snd_pcm_hw_open: alsalib erro r: open '/dev/snd/pcmC0D0p' failed (-524): Unknown error 524 0:00:12.247359789 475 0x7fff540012a0 WARN alsa gstalsasink.c:903:gst_alsasink_open:<audios ink> Error -524 (Unknown error 524) calling snd_pcm_open (&alsa->handle, alsa->device, SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK) 0:00:12.247383030 475 0x7fff540012a0 WARN alsa gstalsasink.c:918:gst_alsasink_open:<audios ink> error: Could not open audio device for playback. 0:00:12.247392733 475 0x7fff540012a0 WARN alsa gstalsasink.c:918:gst_alsasink_open:<audios ink> error: Playback open error on device 'sysdefault:CARD=vc4hdmi0': Unknown error 524 0:00:12.247556085 475 0x555620883dc0 ERROR gst-play gstplay.c:1084:error_cb:<play0> ERROR: from element /GstBin:audioOutput/GstAlsaSink:audiosink: Could not open audio device for playback. 0:00:12.247575826 475 0x555620883dc0 ERROR gst-play gstplay.c:1086:error_cb:<play0> Additional debug info: /usr/src/debug/gstreamer1.0-plugins-base/1.24.10/ext/alsa/gstalsasink.c(918): gst_alsasink_open (): /GstBin:audioOutput/GstAlsaSink:audiosink: Playback open error on device 'sysdefault:CARD=vc4hdmi0': Unknown error 524 0:00:12.247597418 475 0x555620883dc0 ERROR gst-play gstplay.c:984:on_error:<play0> Error: Error from element /GstBin:audioOutput/GstAlsaSink:audiosink: Could not open resource for writing. Could not open audio device for playback. /usr/src/debug/gstreamer1.0-plugins-base/1.24.10/ext/alsa/gstalsasink.c(918[ 702.208232] GPIO Button released: keycode=106 ): gst_alsasink_open (): /GstBin:audioOutput/GstAlsaSink:audiosink: Playback open error on device 'sysdefault:CARD=vc4hdmi0': Unknown error 524 (gst-play-error-quark, 0) 0:00:12.247582678 475 0x7fff540012a0 WARN playsink gstplaysink.c:2947:gen_audio_chain:<playsin k> error: Configured audiosink audioOutput is not working.
I am not sure if this is a known qt bug or if I am missing a configuration for qt to recognize my device. Any help is appreciated.