Hello jose
Comprehensive Technical Report: HDMI Audio Output Failure
Operating System: Ubuntu 24.04.2 LTS – 64-bit Desktop Environment: GNOME 46 –
Wayland Kernel: Linux 6.14.0-1005-oem Display: SHARP monitor connected via
DisplayPort → HDMI Audio Hardware: HDA Intel HDMI (card 1) Audio Stack:
PipeWire 1.0.5 with WirePlumber
Problem Summary:
Although the HDMI audio device is correctly detected by the system, no sound is
emitted from the SHARP display connected via DisplayPort. Audio output
functions normally through the built-in analog Line Out, but HDMI audio remains
inactive despite manual routing and configuration.
Detailed Diagnostic Steps:
1. Hardware and Driver Verification:
✅ aplay -l output:
card 1: HDMI [HDA Intel HDMI]
Devices detected: HDMI 0 (device 3), HDMI 1 (device 7), HDMI 2 (device
8)
✅ lsmod confirmed the following modules are loaded:
snd_hda_codec_hdmi
snd_hda_intel
✅ edid-decode output:
Basic audio support present
Audio latency reported: 35 ms
✅ cat /sys/class/drm/*/status indicated one connected output (likely
HDMI-A-1)
2. Direct ALSA Audio Testing:
❌ aplay -D plughw:1,3 → No audio output
❌ ffmpeg -i file.mp3 -f wav - | aplay -D plughw:1,3 → Failed with
Input/output error
⚠️ speaker-test -D plughw:1,3 -c 2 → Audible clicking only (incomplete
signal transmission)
3. PipeWire Audio Routing:
✅ wpctl status showed:
HDMI sink: ID 48 → Built-in Audio Digital Stereo (HDMI)
Active stream from mpv routed to SHARP HDMI:playback_FL/FR
❌ Despite correct routing, audio was emitted through Line Out instead of
HDMI
✅ Commands executed:
bash
wpctl set-default 48
wpctl move <stream-id> 48
→ No effect on HDMI output
4. Playback via MPV and FFmpeg:
✅ Both mpv and ffplay successfully decoded and played the audio file
❌ However, no sound was heard from HDMI despite AO: [pipewire] 48000Hz stereo
2ch floatp being reported
5. Attempt to Enforce Compatible Audio Format:
A configuration file was created at:
~/.config/pipewire/pipewire.conf.d/99-force-16bit.conf with the following
content:
ini
stream.properties = {
audio.format = "S16LE"
}
❌ PipeWire ignored the override; mpv continued using floatp
✅ The configuration was later removed:
bash
rm -r ~/.config/pipewire/pipewire.conf.d
6. Audio Stack Restart:
Commands executed:
bash
systemctl --user restart pipewire pipewire-pulse wireplumber
sudo alsa force-reload
7. HDMI Set as Default Sink:
✅ wpctl set-default 48 executed
✅ wpctl status confirmed HDMI as the default sink
❌ Still, no audio was emitted from the HDMI output
8. EDID and Handshake Validation:
✅ edid-decode confirmed audio support in the display's EDID
❌ ALSA failed to transmit audio to HDMI (Broken pipe errors)
9. Line Out Functionality Verification:
✅ wpctl set-default 37 restored analog output
✅ speaker-test -D plughw:0,0 -c 2 produced expected white noise
✅ mpv successfully played audio through Line Out
🧩 Technical Conclusion:
Component Status
HDMI driver loaded ✅ Yes
HDMI device visible in ALSA & PipeWire ✅ Yes
EDID reports audio support ✅ Yes
ALSA fails to write to HDMI ❌ Yes
PipeWire routes audio to HDMI ✅ Yes
No actual audio from HDMI output ❌ Yes
Analog Line Out functions properly ✅ Yes
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Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2114627
Title:
Persistent HDMI Audio Output Failure on Dell OptiPlex 9020 (Intel
Haswell) in Ubuntu 24.04
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