Hi Marijn, On Mon, Jul 13, 2020 at 5:05 PM Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> wrote: > > Hi Marijn, > > On Sat, Jul 11, 2020 at 4:50 AM Marijn Suijten <marijns95@xxxxxxxxx> wrote: > > > > `Volume` is a special property that not only exists on players but also > > on the transport (see org.bluez.MediaTransport1). A player is not > > attached when the controller does not support FEATURE_CATEGORY_1, which > > is common on headphones without media browsing capabilities. > > > > On such audio devices (headphones, in-ears and the like) Absolute Volume > > is not available unless an external player is registered > > (org.bluez.Media1.RegisterPlayer) and the device sends a volume event > > back after that to set a2dp->volume in transport.c to a valid value > > (causing volume_exists to finally return true). > > > > This [1] mail thread denoting the same issue has a solution to at least > > request capabilities from the controller, but the proposed player object > > is not created on category 2 devices. Any notifications received on > > AVRCP_EVENT_VOLUME_CHANGED (avrcp_volume_changed) that is subsequently > > registered, or handling the result of avrcp_set_volume in > > avrcp_handle_set_volume will be ignored unless said player is present. > > > > This issue is not addressed by adding a fake player but instead dealing > > with the fact that volume is "special" and available on the transport > > regardless of the existence of a player. This is confirmed in > > avrcp_get_capabilities_resp as well which requires a player to register > > any event except AVRCP_EVENT_VOLUME_CHANGED. > > > > The applied solution moves media_transport_update_device_volume out of > > the player and into avrcp_volume_changed/avrcp_handle_set_volume where > > it is unconditionally called. These functions are the only users of > > avrcp_player->set_volume. > > > > Note that the volume member of media_player is never used which seems a > > result of updating from org.bluez.MediaPlayer1 to > > org.mpris.MediaPlayer2.Player in > > 15e421737ccc4696ed567edcc24d178aedb47854, where the volume property [2] > > is left out. > > This is actually on purpose since the volume notification indicates > the volume at the device side we don't want to change the player > volume as well as it would most likely result in duplicating the > volume change both at sink and source, note that the likes of handling > the transport like pulseaudio would already notify the device volume > level change without actually applying any change to the volume > locally. > > > [1]: https://marc.info/?l=linux-bluetooth&m=145337574806153 > > [2]: https://specifications.freedesktop.org/mpris-spec/2.2/Player_Interface.html#Property:Volume > > > > --- > > Hi, > > > > This is is a resend from an earlier mail that didn't comply with the > > contributor guidelines. Seeing that the topic of AVRCP volume is brought > > up recently it is about time to repair it and hereby send it again. > > > > I still have an incomplete patch lying around that synchronizes Volume > > on org.mpris.MediaPlayer2.Player back when this patch was written 6 > > months ago. It'll require some time to get back in to it and finalize > > it, let me know if that's desired. > > > > - Marijn Suijten > > > > profiles/audio/avrcp.c | 12 ++++++++---- > > profiles/audio/media.c | 16 ---------------- > > 2 files changed, 8 insertions(+), 20 deletions(-) > > > > diff --git a/profiles/audio/avrcp.c b/profiles/audio/avrcp.c > > index e2428250e..8370c8a44 100644 > > --- a/profiles/audio/avrcp.c > > +++ b/profiles/audio/avrcp.c > > @@ -3625,12 +3625,13 @@ static void avrcp_volume_changed(struct avrcp *session, > > struct avrcp_player *player = target_get_player(session); > > uint8_t volume; > > > > - if (!player) > > - return; > > - > > volume = pdu->params[1] & 0x7F; > > > > - player->cb->set_volume(volume, session->dev, player->user_data); > > + /* Always update the transport volume, which is separate from the player */ > > + media_transport_update_device_volume(session->dev, volume); > > + > > + if (player) > > + player->cb->set_volume(volume, session->dev, player->user_data); > > } > > > > static void avrcp_status_changed(struct avrcp *session, > > @@ -4378,6 +4379,9 @@ static gboolean avrcp_handle_set_volume(struct avctp *conn, uint8_t code, > > > > volume = pdu->params[0] & 0x7F; > > > > + /* Always update the transport volume, which is separate from the player */ > > + media_transport_update_device_volume(session->dev, volume); > > + > > if (player != NULL) > > player->cb->set_volume(volume, session->dev, player->user_data); > > > > diff --git a/profiles/audio/media.c b/profiles/audio/media.c > > index 993ecb3b3..a0173fdd4 100644 > > --- a/profiles/audio/media.c > > +++ b/profiles/audio/media.c > > @@ -1202,27 +1202,11 @@ static uint32_t get_duration(void *user_data) > > static void set_volume(uint8_t volume, struct btd_device *dev, void *user_data) > > { > > struct media_player *mp = user_data; > > - GSList *l; > > > > if (mp->volume == volume) > > return; > > > > mp->volume = volume; > > - > > - for (l = mp->adapter->endpoints; l; l = l->next) { > > - struct media_endpoint *endpoint = l->data; > > - struct media_transport *transport; > > - > > - /* Volume is A2DP only */ > > - if (endpoint->sep == NULL) > > - continue; > > - > > - transport = find_device_transport(endpoint, dev); > > - if (transport == NULL) > > - continue; > > - > > - media_transport_update_volume(transport, volume); > > - } > > } > > > > static bool media_player_send(struct media_player *mp, const char *name) > > -- > > 2.27.0 > > Applied, Thanks. Note that I did fix some coding style problems. -- Luiz Augusto von Dentz
