Gfilui

I have a CEL-TEC F5A headset.
The spec says:

Bluetooth 4.0, profiles: Headset, Hands free, A2DP, AVRCP/HSP/HFP

It plays nicely with High Fidelity Playback (A2DP sink) profile.

When I want to switch audio input to the headset's microphone, the output profile automatically changes to Headset Head Unit (HFS/HFP) and the quality is terrible - like 8bit sound or something. When I switch it back to A2DP, the input is back to desktop mic.

I've read few of other questions and seems A2DP is expected not to support input, right? But the HFP part in HFS/HFP is High Fidelity Playback I guess? That sounds like it could work as a headset and still not sound like 1950's phone.

How could I simplify switching between the profiles so that it is HFS/HFP when I talk and A2DP when I listen? E.g. as a push-to-talk.

Ubuntu 17.10, no sound customization IIRC, everything latest.
https://www.kabelmanie.cz/cel-tec-f5a-active-noise-bluetooth-stereo-sluchatka-s-mikrofonem/

My output:

$ pactl list cards
Card #0
 Name: alsa_card.pci-0000_00_03.0
...

Card #4
 Name: bluez_card.00_19_5D_25_6F_6C
 Driver: module-bluez5-device.c
 Owner Module: 30
 Properties:
 device.description = "F5A"
 device.string = "00:19:5D:25:6F:6C"
 device.api = "bluez"
 device.class = "sound"
 device.bus = "bluetooth"
 device.form_factor = "headset"
 bluez.path = "/org/bluez/hci0/dev_00_19_5D_25_6F_6C"
 bluez.class = "0x240404"
 bluez.alias = "F5A"
 device.icon_name = "audio-headset-bluetooth"
 device.intended_roles = "phone"
 Profiles:
 a2dp_sink: High Fidelity Playback (A2DP Sink) (sinks: 1, sources: 0, priority: 10, available: yes)
 headset_head_unit: Headset Head Unit (HSP/HFP) (sinks: 1, sources: 1, priority: 20, available: yes)
 off: Off (sinks: 0, sources: 0, priority: 0, available: yes)
 Active Profile: a2dp_sink
 Ports:
 headset-output: Headset (priority: 0, latency offset: 0 usec, available)
 Part of profile(s): a2dp_sink, headset_head_unit
 headset-input: Headset (priority: 0, latency offset: 0 usec)
 Part of profile(s): headset_head_unit

The problem here is not that the microphone does not work, but rather that the audio quality worsens when it is activated.

Based on this article I fear that Bluetooth won't give me the pleasure of hearing a quality sound and speak over the headset at the same time. :/

Not accepting this answer though, I am still hoping someone will come up with some way to do so.

I was about to return the headset and wait for Bluetooth 5.0 headset, but then realized, that's the best functionality I can get with my BT 4.0 laptop. So I kept them.

Still, listening to a French guy over 16 bit 8000 Hz audio wasn't really the right way to have a meeting. For few days, I was switching between the two modes using Ubuntu's sound settings dialog, but that's really, really annoying as you can imagine.

So I wrote this script leveraging pacmd which toggles between the 2 modes:

• Crappy audio, microphone on


• Near-CD quality audio, microphone off

It is not polished, has some dead code, and I use my own phones ID's, but it may be an inspiration for your own script. Latest version here.

#!/bin/bash

#### Restart Bluetooth
if [ "$1" == "resetBT" ] ; then
 sudo rfkill block bluetooth && sleep 0.1 && sudo rfkill unblock bluetooth;
 exit;
fi;

#### Toggle listen/speak
if [ "$1" == "" -o "$1" == "toggle" ] ; then
 LINE=`pacmd list-sinks | grep '(name:|alias)' | grep -B1 F5A | head -1`
 if [ "$LINE" == "" ] ; then echo "F5A headset not found"; exit; fi

 SINK_NAME="bluez_sink.00_19_5D_25_6F_6C.a2dp_sink"
 if $(echo "$LINE" | grep $SINK_NAME &> /dev/null) ; then
 echo "Detected quality sound output, that means we can't speak; switch that."
 $0 speak;
 else
 echo "Quality sound not found, switch to the good sound."
 $0 listen;
 fi
fi

#### Change the output to F5A
if [ "$1" == "listen" ] ; then
 LINE=`pacmd list-sinks | grep '(name:|alias)' | grep -B1 F5A | head -1`
 if [ "$LINE" == "" ] ; then echo "F5A phones not found"; exit; fi
 # name: <bluez_sink.00_19_5D_25_6F_6C.headset_head_unit>

 ## Get what's between <...>
 SINK_NAME=`echo "$LINE" | tr '>' '<' | cut -d'<' -f2`;

 ## The above gives an ID according to the active profile.
 ## To set manually:
 #SINK_NAME="bluez_sink.00_19_5D_25_6F_6C.headset_head_unit"
 #SINK_NAME="bluez_sink.00_19_5D_25_6F_6C.a2dp_sink"

 ## Switch the output to that.
 echo "Switching audio output to $SINK_NAME";
 pacmd set-default-sink "$SINK_NAME"

 #### Change profile to quality output + no mic. From `pacmd list-cards`:
 CARD="bluez_card.00_19_5D_25_6F_6C"
 PROFILE="a2dp_sink" 
 echo "Switching audio profile to $PROFILE";
 pacmd set-card-profile $CARD $PROFILE
 exit;
fi;

#### Input
if [ "$1" == "speak" ] ; then
 ## Change profile to crappy output + mic. From `pacmd list-cards`:
 CARD="bluez_card.00_19_5D_25_6F_6C"
 pacmd set-card-profile $CARD headset_head_unit

 LINE=`pacmd list-sources | grep '(name:|alias)' | grep -B1 F5A | head -1`
 if [ "$LINE" == "" ] ; then echo "F5A mic not found"; exit; fi
 SOURCE_NAME=`echo "$LINE" | tr '>' '<' | cut -d'<' -f2`;
 #SOURCE_NAME="bluez_source.00_19_5D_25_6F_6C.headset_head_unit"
 #SOURCE_NAME="bluez_sink.00_19_5D_25_6F_6C.a2dp_sink.monitor"
 echo "Switching audio input to $SOURCE_NAME";
 pacmd set-default-source "$SOURCE_NAME" || echo 'Try `pacmd list-sources`.';
fi;


#### Resources:

## Why this is needed
# https://jimshaver.net/2015/03/31/going-a2dp-only-on-linux/

## My original question
# https://askubuntu.com/questions/1004712/audio-profile-changes-automatically-to-hsp-bad-quality-when-i-change-input-to/1009156#1009156

## Script to monitor plugged earphones and switch when unplugged (Ubuntu does that, but nice script):
# https://github.com/freundTech/linux-helper-scripts/blob/master/padevswitch/padevswitch

Hope this helps someone :) Still, I am not accepting this answer either, hoping for some magic that will enable good sound with mic on.