Hi Luiz, Thanks for the comments. I am testing with this UE-mini Boom speaker. http://the-gadgeteer.com/2013/11/22/ue-mini-boom-portable-bluetooth-speaker-review/ This BT speaker has two buttons 'Volume Up' and 'Volume Down', but lack of player related buttons, like next/prev track, shuffle/play/pause. I think that is why it advertised to support only category 2 feature. Looking at audio/avrcp.c, set_volume is one of the avrcp_player_cb callback functions, plus that avrcp_volume_changed() checks for the existence of an avrcp_player struct before handling the event. Seems that avrcp_player structure is designed to cover both category 1 and category 2 features. Maybe we should change the condition to if (!(controller->features & (AVRCP_FEATURE_CATEGORY_1 | AVRCP_FEATURE_CATEGORY_2))) instead? So that the set volume cmd and volume change event can work correctly on those peripherals who has volume button only. I will send a patch for that later. Hsin-yu On Wed, Jan 20, 2016 at 11:59 PM, Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> wrote: > Hi Hsin-yu, > > On Tue, Jan 19, 2016 at 2:06 PM, Hsin-yu Chao <hychao@xxxxxxxxxxxx> wrote: >> Hi, >> I am working on AVRCP for Chromium OS using MediaPlayer dbus API and >> noticed a problem while testing the media buttons on various BT >> speaker/headsets. In profile/audio/avrcp.c there is a check for >> supported feature before an avrcp_player is created: >> >> /* Only create player if category 1 is supported */ >> if (!(controller->features & AVRCP_FEATURE_CATEGORY_1)) >> return; > > Category 1 is player category thus why we check it. > >> The SDP record of my BT speaker has feature == >> AVRCP_FEATURE_CATEGORY_2 (monitor/amplifier). My understanding is that >> this feature is associated with volume changed event and >> SetAbsoluteVolume command. > > And GetCapabilities as well since otherwise we cannot subscribe to > volume changes. > >> But with this check, volume changed events are unable to pass up to >> registered player app in my case. I tried commented out these few >> lines and rebuild bluetoothd, after that volume change events works >> perfect. >> >> What is the reason to create player only when it supports category 1 feature? > > I don't recall now but I guess all the headset we encountered had this > feature bit set, note that this is the category of a target record but > perhaps it is valid after all. Btw, is this a BT Speaker of yours a > device on the market already? > > > -- > Luiz Augusto von Dentz -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
