Hi Niek, On Tue, Jun 21, 2016 at 1:08 AM, Niek Vlessert <niekvlessert@xxxxxxxxx> wrote: > Hello list, > > I've developed some player thing with chiptune music in the browser and I > wanted an Android app using Webview to be able to change tracks and see the > titles with my car audio system. After some experimenting I got it done > using the MediaSession/PlaybackState/MediaMetadata Android provides. However > I wondered about album art. After experimenting and a lot of google I'm > currently here; > > - Album art was standardised in AVRCP 1.6 although older versions had some > openings that could be used but nobody did. > - As far as I know no car media system supports AVRCP 1.6 yet, but there > seems to be some reference platform for car manufacturers; AudioVideoSDK > 3.0, that supports it. > - Bluez supports AVRCP up to 1.5 Actually we can do up to 1.6 but just the mandatory commands which don't include the ones necessary for cover art, etc. > - I can't find any evidence it's been worked on > - MediaMetadata has support for images, but I suppose that's non-bluetooth > related (Chromecast?). Android has support only to 1.3, there are vendors that extend to 1.4/1.5 like samsung but they have to change all the way from HAL to java to interface this to the application. > - Some car systems with an iPhone can use the internet connection provided > by the phone to download album art from cddb, which is why some people > believe iPhone supports AVRCP 1.6. I don't think that's implemented in non > iPhone devices? I don't think so either, even in case of chromecast it is a custom protocol by the application or the full tab if you are using chrome to cast. > - Some others support it in the MP3 file on the local SD card, but I'm not > using MP3. > - Currently I'm testing my little Android app in conjunction with an Ubuntu > VM on my iMac, because Ubuntu can run in A2DP sink mode thanks to Bluez. > - I'm testing AVRCP with D-feet, previous/next etc. works fine!! You can use tools/bluetooth-player if you want to control it from the command line, another alternative is to use tools/mpris-proxy and then control it using a MPRIS controller. > - Using Wireshark on my VM I can see what's going on > > So onto my questions: > > - Is there any work being done on this? > - Is there any software on Linux out there to test AVRCP 1.6? I can't find > any. I don't think anyone has come to implement AVRCP 1.6 for any OS actually, at least not the commands necessary for cover art transfer. > - Would you consider it possible to put the right hex into my Android app > and transmit that to my Bluetooth connection so I can implement it without > the Android Bluez stack supporting it? If target devices will ever support > it... Since it's serial communication, I thought why not? I never did > anything like this with Bluetooth programming so forgive my ignorance. :) > Something like this: create L2CAP channel with the Cover Art UUID. Wait for > response; encode picture in the right data packages, and here we go. Leave > other Bluetooth communication requirements to Android. You can do whatever you want, but since it would be non-standard this would limit a lot the usage. > - Or maybe I could use the cddb support? Maybe it's possible to redirect > traffic to cddb to somewhere else, provide the cddb interface and offer the > image like that? I know, it's horrible... ;) Also non-standard, perhaps investing time in doing a AVRCP 1.6 would be better. > And of course I'm ready to test. > > Regards, > > Niek Vlessert > -- > 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 -- 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
