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Posts: 4
Registered: ‎03-10-2017

AVRCP list of media players only returns active player

I was following the example "WT32i & iWRAP6.0 -– AVRCP example 1: list media players and set a media player" using the WT32i DevKit and an iPhone 6P.  It seems that only the "active" media player is listed in my case. What is the recommended method to list all media players on the device?   Besides the native player, I have noticed that other players have the "PLAYER ID" value of 2.  I'm new to the WT32i and am not clear if I'm dealing with an iOs issue or not using the WT32i properly.  I do understand that not all players can be browsed but I am hoping they can be listed.  Note: About 10 days ago I posted this question in the knowledge-base as a comment to the article.  I'm reposting it here in hopes for a reply.

 

// Very generic settings :)
SET DEVKIT
WRAP THOR AI (6.0.0 build 952)
Copyright (c) 2003-2014 Bluegiga Technologies Inc.
READY.

//Note: I am then establishing the connection using the phones bluetooth menu
//not iWrap.
//The AVRCP and AVRCP browsing links are opened automatically. LIST LIST 5 LIST 0 CONNECTED AVRCP 672 0 0 18 0 0 7c:01:91:85:58:da 17 INCOMING ACTIVE SLAVE ENCRYPTED 0 LIST 1 CONNECTED A2DP 672 0 0 18 0 0 7c:01:91:85:58:da 19 INCOMING ACTIVE SLAVE ENCRYPTED 0 LIST 2 CONNECTED HFP 667 0 0 18 8d 8d 7c:01:91:85:58:da 3 INCOMING ACTIVE SLAVE ENCRYPTED 0 LIST 3 CONNECTED AVRCP 672 0 0 18 8d 8d 7c:01:91:85:58:da 1b INCOMING ACTIVE SLA VE ENCRYPTED 0 LIST 4 CONNECTED A2DP 672 0 0 17 8d 8d 7c:01:91:85:58:da 19 INCOMING ACTIVE SLAV E ENCRYPTED 0

 

//Response when playing a video stream on a website
// Note that the result is the same if i use @0 (AVRCP)
// or @3 (AVRCP Browsing channel)

@3AVRCP BROWSE LIST 0 0 f 0
AVRCP_BROWSE 3 GET_FOLDER_ITEMS UIDC 0000 ITEMS 0001 < < PLAYER ID 0002 TYPE 01
SUBTYPE 00000000 PLAY_STATUS PAUSED FEATURES 0000000000b701000000000000000000 NA
ME 0014 Unknown Media Player > >

 

//Response when playing the native iPhone music player
@3AVRCP BROWSE LIST 0 0 f 0
AVRCP_BROWSE 3 GET_FOLDER_ITEMS UIDC 0000 ITEMS 0001 < < PLAYER ID 0001 TYPE 01
SUBTYPE 00000000 PLAY_STATUS PAUSED FEATURES 0000000000b7011c0200000000000000 NA
ME 0005 Music > >

 

//Response when playing Pandora
@3AVRCP BROWSE LIST 0 0 f 0
AVRCP_BROWSE 3 GET_FOLDER_ITEMS UIDC 0000 ITEMS 0001 < < PLAYER ID 0002 TYPE 01
SUBTYPE 00000000 PLAY_STATUS PLAYING FEATURES 0000000000b701000000000000000000 N
AME 0007 Pandora > > 

 

Posts: 343
Registered: ‎10-07-2015

Re: AVRCP list of media players only returns active player

Hello,

The command that you use to list media players (AVRCP BROWSE LIST 0 0 f 0) is correct. The list that you receive as a response depends on the remote end (iPhone with iOS in your case) and the iWRAP software doesn't have any control over it.

 

Regards,

Bartosz

Posts: 4
Registered: ‎03-10-2017

Re: AVRCP list of media players only returns active player

Can you offer any suggestion on how this could be done?  Does it require iAp?  I've seen a few devices that do seem to have the ability to access other media services on the phone.

 

 

Posts: 343
Registered: ‎10-07-2015

Re: AVRCP list of media players only returns active player

Hello,

Are you saying that you have a device that is able to retrieve all media players from the same iPhone, while the iWRAP lists only one?

 

Regards,

Bartosz

Posts: 4
Registered: ‎03-10-2017

Re: AVRCP list of media players only returns active player

Unfortunately it was a few months ago using a rental car.  Honestly I'm now wondering if I was connected via USB at the time.

 

Under section 2.2.4.6, the apple bluetooth design guidelines document states "Currently only the built-in Music app supports browsing."   It also states "All iOS devices running iOS 6.0 or later support AVRCP Browsing."  I had read this earlier and eluded to it in my first post.  My assumption at the time was that since the device supported browsing I could get a list of media players, but that players themselves may not support browsing (of their media).  This does not appear to be the case.  I do find it odd that once the media player is selected that it will respond to supported browse commands.  I should also mention that using the AVRCP BROWSE SETPLAYER {ID} command also fails unless you send the {ID} of the active player.

 

Do you see any possibility that iAp could help with this?  Are you aware of a definitive apple response on this topic or can you suggest the best place to post the question?

Posts: 343
Registered: ‎10-07-2015

Re: AVRCP list of media players only returns active player

Hello,

 

I really don't think that this could be done using the Bluetooth protocol - this seems to be a phone-specific behavior which cannot be controlled from iWRAP side.

You could contact the manufacturer of the remote device if listing inactive audio players is possible at all.

 

Regards,

Bartosz