ULT WEAR Enhanced Support

[RealCrystalNight]

It would be nice to have equaliser modification support.
Hi I made a fork and added device images + equalizer modification (kinda flaky)
https://github.com/RealCrystalNight/SonyHeadphonesClient-fork if you want to check it out.
(I admit it's a bit of a hack but some ideas I had which were missing here)

[mos9527]

Thanks for the work you've put in. Some questions however:

• Can you elaborate on how 'Equaliser Modification' support is being 'added'?
  If it's the Custom EQ (User Settings) presets I believe it has always worked for currently supported devices.
  Taking a glance at your commit logs it seems that this is uniquely a ULT-series problem. If that's the case - please revise the issue title to something like 'ULT WEAR Support'.
• I see you are trying to get current playing tracks via MPRIS directly, this also implies a OS dependency which we never had before - does the original path via MDR commands not work for your device?
• Seems like you'd like to change to Custom EQ whenver the sliders are touched - frankly I should've disabled the sliders whenever it's NOT in Custom EQ, which matches the app. I should disable it in future releases.
• As for headphone images...oh, you only added the ULT one. Regardless - I'd wish we could have it but one'd think twice before introducing copyrighted images into a MIT-licensed FOSS project. Good idea, but maybe not applicable in the reference Client UI here.

In all your work on ULT WEAR compatibility is quite valuable. If it's possible have your LLM agent summarize the issues/bugfixes it has proposed and hand that over to us so we can properly implement those features.

That reminds me. I really should've added contribution guidelines...

[RealCrystalNight]

Hey there,
To answer the first point, yes - this is a uniquely an ULT WEAR protocol issue. Equaliser editing was broken for ULT model headphones which meant that I could only edit the user set equalizer through the app which inspired the fork. Issue title will be changed accordingly as per your suggestion.
As for the second point, I tested the built tool on CachyOS and the played a song via Elisa which did not show up as currently playing. The track metadata was blank during my testing because Linux requires mpris-proxy to forward D-Bus MPRIS metadata over Bluetooth AVRCP. Running systemctl --user enable --now mpris-proxy fixed it. I also added a periodic auto-poll in the GUI so track info updates every 5s without manual refresh. The CLI now-playing command that reads MPRIS directly is just a debugging convenience, it's not the main path.
To address the third point, I agree that's a good point only custom modes such as user settings and "custom" should be editable.
Lastly, I did not mean to push the ULT images but yeah this is actually derived from this https://raw.githubusercontent.com/RealCrystalNight/SonyHeadphonesClient-fork/refs/heads/rewrite/client/Resources/model_images.json which is a list of CDN links from Sony to all the images of their headphones and so I don't think it would be problematic to get the image from the CDN and cache it for the user. Not exactly sure what the best way is to fit it into the UI so the design you see in the screenshot is a proof of concept.

Agent Summary

1. EQ Bands — ULT WEAR Protocol Incompatibility

Root cause: The existing code queries and writes EQ band data using PRESET_EQ (0x00) inquired type. ULT WEAR returns 0 bands on that path. Band data only arrives through PRESET_EQ_AND_ULT_MODE (0x03), which bundles preset ID, ULT mode (OFF/ULT1/ULT2), and band steps in a single packet. The device also silently ignores band writes sent via PRESET_EQ — they must go through PRESET_EQ_AND_ULT_MODE.

Changes in libmdr/src/HeadphonesV2T1.cpp:

• Added handler for PRESET_EQ_AND_ULT_MODE responses: deserializes EqEbbParamEqAndUltMode, extracts bandSteps into mEqConfig/mEqClearBass, but only when res.presetId == mEqPresetId.current — this prevents stale INIT responses from overwriting user edits
• Added handler for SOUND_EFFECT responses: deserializes and updates mSoundEffect
• Patched the PRESET_EQ handler: when bands.size() == 0 (as ULT returns), keeps existing band values rather than zeroing them
• Track metadata handler now guards against overwriting non-empty titles/albums/artists with empty strings

Changes in libmdr/src/HeadphonesV2.cpp:

• Init now conditionally queries PRESET_EQ_AND_ULT_MODE and SOUND_EFFECT when the device advertises those functions in its support table
• Commit logic restructured: when device supports PRESET_EQ_AND_ULT_MODE, ALL EQ changes (preset + bands + clear bass + ULT mode) are sent as a single combined EqEbbParamEqAndUltMode packet. The commit sends band steps in the device's 6-byte (5-band + Clear Bass) or 10-byte (10-band) format, gated on whether bands were actually dirty
• ULT-mode-only changes (no EQ edits) get a minimal commit to avoid unnecessary band resends
• Added RequestRefreshEQV2() and RequestRefreshPlaybackV2() task methods for targeted state polling

Changes in libmdr/include/mdr/:

File	Additions
ProtocolV2.hpp	ULT_SOUND_EFFECT_ASSIGN (0x58), CUSTOMIZABLE_SOUND_EFFECT (0x59) function types
ProtocolV2T1.hpp	5 missing EqEbbInquiredType values (0x33–0x40), SOUND_EFFECT_FLAT (0x05), SOUND_EFFECT_LIVE (0x06)
Headphones.hpp	MDRProperty<EqUltMode> mEqUltMode, MDRProperty<SoundEffectType> mSoundEffect, two new task declarations

2. Now Playing / MPRIS

• The standard GetPlayParam AVRCP path works on ULT WEAR — no protocol changes needed
• mpris-proxy is required on Linux (documented limitation). The GUI auto-starts it via systemctl --user start mpris-proxy on init
• GUI polls playback metadata every 5 seconds during idle via RequestRefreshPlaybackV2() (instead of full sync)
• CLI now-playing command reads MPRIS D-Bus directly via Python's dbus module as a debug convenience only

3. Editable Presets Only

Client.cpp DrawDeviceControlsSound(): when band sliders or Clear Bass are touched and the current preset is not CUSTOM or one of USER_SETTING1..5, the preset is auto-switched to CUSTOM.

4. Device Images

• model_images.json built from Sony's GraphQL API at https://v1.api.data-gateway.seeds.services/graphql (key extracted from libcloudmodelinfo.so in the official Sony Headphones Connect APK)
• CDN URLs at https://hpc-image.data-gateway.seeds.services/{uuid}.png are unauthenticated and publicly accessible
• Cached to disk by model name, with fallback to generic device_default.png silhouette
• ImageLoader.hpp/ImageLoader.cpp uses stb_image to load PNGs into SDL textures
• ModelImageDB.hpp does simple JSON prefix-scan lookup

[mos9527]

Thanks for the thorough response! Can you perchance file a PR with only the ULT/EQ fixes for that to be merged in?

I'll update the docs on MPRIS in the README myself once that's merged - having the app manipulate the OS-level services is quite out of scope, and I'd like to leave it to users themselves to configure their own distros if they'd like to fix it.

As for device images, I'm going to push back on the idea for now. Again - copyright (see also https://github.com/mos9527/SonyHeadphonesClient/tree/rewrite?tab=contributing-ov-file). Thanks for the research there however - I believe a future WinUI frontend build (possibly with a different license) by @Amrsatrio could really make use of that ;)

[mos9527]

Hi, after reviewing - we'll implement your proposed fixes later ourselves. A PR won't be necessary - please wait as we'd land the fix alongside a couple more in a hopefully near future.

This issue will be closed in due time.