Arch Linux

While your headphone is connected via Bluetooth, what are the outputs of the following two commands for you?

LANG=C pactl list cards | grep 'Name: bluez_card' | sed -E 's|^.*Name: (bluez_card.*)|\1|' | xargs -I % pactl send-message /card/%/bluez list-codecs

LANG=C pactl list cards | grep 'Name: bluez_card' | sed -E 's|^.*Name: (bluez_card.*)|\1|' | xargs -I % pactl send-message /card/%/bluez get-codec

With 15.0-2:

~ $ LANG=C pactl list cards | grep 'Name: bluez_card' | sed -E 's|^.*Name: (bluez_card.*)|\1|' | xargs -I % pactl send-message /card/%/bluez list-codecs
[{"name":"sbc","description":"SBC"},{"name":"sbc_xq_453","description":"SBC XQ 453kbps"},{"name":"sbc_xq_512","description":"SBC XQ 512kbps"},{"name":"sbc_xq_552","description":"SBC XQ 552kbps"}]

~ $ LANG=C pactl list cards | grep 'Name: bluez_card' | sed -E 's|^.*Name: (bluez_card.*)|\1|' | xargs -I % pactl send-message /card/%/bluez get-codec
"sbc"


With 15.0-3:

~ $ LANG=C pactl list cards | grep 'Name: bluez_card' | sed -E 's|^.*Name: (bluez_card.*)|\1|' | xargs -I % pactl send-message /card/%/bluez list-codecs
[{"name":"sbc","description":"SBC"},{"name":"sbc_xq_453","description":"SBC XQ 453kbps"},{"name":"sbc_xq_512","description":"SBC XQ 512kbps"},{"name":"sbc_xq_552","description":"SBC XQ 552kbps"},{"name":"ldac_hq","description":"LDAC (High Quality)"},{"name":"ldac_sq","description":"LDAC (Standard Quality)"},{"name":"ldac_mq","description":"LDAC (Mobile Quality)"}]

~ $ LANG=C pactl list cards | grep 'Name: bluez_card' | sed -E 's|^.*Name: (bluez_card.*)|\1|' | xargs -I % pactl send-message /card/%/bluez get-codec
"ldac_hq"

Sounds like a bug in upstream/hardware, same headphones: https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/issues/1124

If you think it's indeed the case, I assume this bug report can be closed..

Could you try to run the following with 15.0-3 and test if you still don't have sound?
(It will switch the codec from the autoselected "ldac_hq" to "ldac_sq".)

LANG=C pactl list cards | grep 'Name: bluez_card' | sed -E 's|^.*Name: (bluez_card.*)|\1|' | xargs -I % pactl send-message /card/%/bluez switch-codec '"ldac_sq"'

If still no sound, try the following (switch to "ldac_mq") ('Mobile Quality', supposedly the least good):

LANG=C pactl list cards | grep 'Name: bluez_card' | sed -E 's|^.*Name: (bluez_card.*)|\1|' | xargs -I % pactl send-message /card/%/bluez switch-codec '"ldac_mq"'

And if still no sound, or if sound quality is bad, you can switch to SBC codec used by PulseAudio 15.0-2:

LANG=C pactl list cards | grep 'Name: bluez_card' | sed -E 's|^.*Name: (bluez_card.*)|\1|' | xargs -I % pactl send-message /card/%/bluez switch-codec '"sbc"'


Please kindly report back your result(s) about which command enables your headphone to play sound.

Thanks for your help in debugging the issue.

I don't have any sound with any of "ldac_hq", "ldaq_sq", "ldac_mq", only switching to "sbc" helps (for completenes: "sbc_xq_453", "sbc_xq_512" and "sbc_xq_552" also work).

LDAC support in GStreamer indeed can be the culprit.

Meanwhile, I think you could use your headphone with the "sbc" codec, or with a higher-quality variant like "sbc_xq_512" or "sbc_xq_552", e.g.:

LANG=C pactl list cards | grep 'Name: bluez_card' | sed -E 's|^.*Name: (bluez_card.*)|\1|' | xargs -I % pactl send-message /card/%/bluez switch-codec '"sbc_xq_512"'

TLDR for @devs:

pulseaudio-bluetooth 15.0-3: upstream issue: no audio when using LDAC codecs with some headphones (e.g. Sony XM4)

FYI I revived the pulseaudio issue https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/issues/1124, and it looks like they already have a patch which did fix a problem for me.

@crem Nice work! So it turns out this is an "upstream+" issue.
PulseAudio uses GStreamer for LDAC. GStreamer creates a not fully LDAC-conformant RTP header.

The PulseAudio patch* works around that GStreamer issue by bypassing GStreamer rtpldacpay element when sending LDAC payload.
(* patch linked by PA dev @igor.v.kovalenko in this comment: https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/issues/1124#note_1265866 )

Not sure what's the best course of action for Arch. The patch fixes the issue but currently it is not part of a Merge Request.

Though as pulseaudio-bluetooth 15.0-3 is in Testing, I'd apply the fix for now and let testers try it.
Seems completely safe to add this patch since it only changes one PulseAudio file specific to Bluetooth GStreamer LDAC codec usage:
"src/modules/bluetooth/a2dp-codec-ldac-gst.c"

I would prefer to patch GStreamer instead of hacking around the problem in PulseAudio.

FYI they have merged the workaround patch to pulseaudio, https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/merge_requests/689