[Android 7.0+] AppRadio Unchained Rootless

[sideshowbob84]

I continued working on AAUnchained for another month.
Short progress report:

General:
- App can now completely reset to initial state so it can be started again
- Implemented start / stop when USB to head unit connected / disconnected
- Powerlock added so phone will never sleep when AAUnchained is active

Protocol
- Did some more testing with different emulators regarding different protocol versions
- Made lots of sensor status messages (like day/night, odometer etc.) working
- Video and audio focus messages are now supported which means that you can now jump back to the head unit and return to the mirrored phone again without losing the connection

Touch improvements:
- Multitouch is now working
- Touch compensates for black bars because of different aspect ratio between head unit and phone

More testing:
- Bought a Samsung S22+ for testing with Android 12 & high performance hardware
- No artefacts in video anymore (there were some on my old Nexus 6)
- Audio delay is down to 200 milliseconds (was 800 - 1000 on Nexus 6)

I am going to make a new demo video soon.

Hi,
i am very interested in the new App version. But it is not available at the moment, correct? The App AppRadio Unchained Rootless available at the playstore is another App, correct?
Thanks a lot and kind regards

 

[Area51©]

Hi,
i am very interested in the new App version. But it is not available at the moment, correct? The App AppRadio Unchained Rootless available at the playstore is another App, correct?
Thanks a lot and kind regards

No it's not available and it's a completely different app. Unfortunately there's a huge snag . Not all audio can be captured and sent to the head unit. I described it a few posts back. The main issue is that voice prompts from navigation apps can't be captured and that's one of the main apps you want to use while driving.

I can only work around that on a rooted phone. But the average user doesn't have a rooted phone.
Other possible solutions would be some loopback audio device. Like Bluetooth audio to wifi. Or a USB audio loopback device. But these complicate operation enormously and may not always work so it's not ideal.
So that's what holding back the development currently.

By the way, the app could never be in the Play store as Google won't allow it. Obviously it's not the way they want you to use your Android Auto head unit. It's not a real problem as you can still sideload apps.

Using Android is like using Windows without an administrator account. Basically Google is the administrator who decides what is good for you. Supposedly for security reasons but often for commercial reasons. Example: ad blocking apps are not allowed in the Play store and Google does everything to make it difficult to implement such an app. They don't want anything blocking their own ads.
Another example: wireless casting to Miracast devices. Once there was support for that in Android. Then Google developed Chromecast. Since then no support for Miracast in Google phones.

 

[sideshowbob84]

No it's not available and it's a completely different app. Unfortunately there's a huge snag . Not all audio can be captured and sent to the head unit. I described it a few posts back. The main issue is that voice prompts from navigation apps can't be captured and that's one of the main apps you want to use while driving.

I can only work around that on a rooted phone. But the average user doesn't have a rooted phone.
Other possible solutions would be some loopback audio device. Like Bluetooth audio to wifi. Or a USB audio loopback device. But these complicate operation enormously and may not always work so it's not ideal.
So that's what holding back the development currently.

By the way, the app could never be in the Play store as Google won't allow it. Obviously it's not the way they want you to use your Android Auto head unit. It's not a real problem as you can still sideload apps.

Using Android is like using Windows without an administrator account. Basically Google is the administrator who decides what is good for you. Supposedly for security reasons but often for commercial reasons. Example: ad blocking apps are not allowed in the Play store and Google does everything to make it difficult to implement such an app. They don't want anything blocking their own ads.
Another example: wireless casting to Miracast devices. Once there was support for that in Android. Then Google developed Chromecast. Since then no support for Miracast in Google phones.

Thanks for clarification! When i was using Android Auto with my old phone. It was always additonally connected via Bluetooth while it was connected via cable to my head unit. But i do not know how sound was transfered, so i think this is something you already checked.
Thanks a lot nevertheless. An App like yours would still be great.

 

[tiho5]

No it's not available and it's a completely different app. Unfortunately there's a huge snag . Not all audio can be captured and sent to the head unit. I described it a few posts back. The main issue is that voice prompts from navigation apps can't be captured and that's one of the main apps you want to use while driving.

I can only work around that on a rooted phone. But the average user doesn't have a rooted phone.
Other possible solutions would be some loopback audio device. Like Bluetooth audio to wifi. Or a USB audio loopback device. But these complicate operation enormously and may not always work so it's not ideal.
So that's what holding back the development currently.

By the way, the app could never be in the Play store as Google won't allow it. Obviously it's not the way they want you to use your Android Auto head unit. It's not a real problem as you can still sideload apps.

Using Android is like using Windows without an administrator account. Basically Google is the administrator who decides what is good for you. Supposedly for security reasons but often for commercial reasons. Example: ad blocking apps are not allowed in the Play store and Google does everything to make it difficult to implement such an app. They don't want anything blocking their own ads.
Another example: wireless casting to Miracast devices. Once there was support for that in Android. Then Google developed Chromecast. Since then no support for Miracast in Google phones.

Make it for rooted devices only. We see many apps like that. For example skvalex call recorder. But many people still use it and even root for such apps.

After all if one wants to get more out of their phone, they'd root it.

 

[Area51©]

Make it for rooted devices only. We see many apps like that. For example skvalex call recorder. But many people still use it and even root for such apps.

After all if one wants to get more out of their phone, they'd root it.

Ok I am working a bit on it. Now have a proof of concept working that captures all audio on a rooted phone. It requires Android 10 or higher but doesn't require to install some Magisk module . I have only tested it on Android 11.

I think I found a new way to capture REMOTE_SUBMIX audio. It requires root but doesn't need to be a system app (=signed with the manufacturer key). Now have to see if that also works with Android 12 and 13.

 

[stargate125645]

Ok I am working a bit on it. Now have a proof of concept working that captures all audio on a rooted phone. It requires Android 10 or higher but doesn't require to install some Magisk module . I have only tested it on Android 11.

I think I found a new way to capture REMOTE_SUBMIX audio. It requires root but doesn't need to be a system app (=signed with the manufacturer key). Now have to see if that also works with Android 12 and 13.

Which phone do you have rooted?

 

[Area51©]

Which phone do you have rooted?

My old Nexus 6 running Lineage 18 = Android 11. It works, it's a bit slow but fine for development.

I guess you are looking into rooting. I did the same for my Samsung S8+. There's descriptions on how to do it but it's pretty complicated and not that clear. I think I found a write up that might work but still haven't rooted it. There's also features that won't work anymore when you root your phone. And if you have a new phone, warranty is void.
This is the reason why I think not that many people are going to root their phone just to use an app. I am not even considering to root my new S22+.

 

[stargate125645]

My old Nexus 6 running Lineage 18 = Android 11. It works, it's a bit slow but fine for development.

I guess you are looking into rooting. I did the same for my Samsung S8+. There's descriptions on how to do it but it's pretty complicated and not that clear. I think I found a write up that might work but still haven't rooted it. There's also features that won't work anymore when you root your phone. And if you have a new phone, warranty is void.
This is the reason why I think not that many people are going to root their phone just to use an app. I am not even considering to root my new S22+.

I will not be rooting my primary phone for those stated reasons. But, I would consider using an older phone for that purpose. I would also consider this app useful even if I don't get to transfer navigation directions over car audio provided we can switch between stock Android Auto and your application prior to turning on the car. I think there are options to make this work!

 

[Area51©]

I will not be rooting my primary phone for those stated reasons. But, I would consider using an older phone for that purpose. I would also consider this app useful even if I don't get to transfer navigation directions over car audio provided we can switch between stock Android Auto and your application prior to turning on the car. I think there are options to make this work!

For me navigation and playing music would be the most important uses cases. Can you tell me what you would be yours?

Also other people reading this, what would be your main reason to use a phone mirror app? Just to give me some clue what is important to have working.

 

[tiho5]

For me navigation and playing music would be the most important uses cases. Can you tell me what you would be yours?

Also other people reading this, what would be your main reason to use a phone mirror app? Just to give me some clue what is important to have working.

Everything actually.

I would look at my calendar and see what are my next events and tasks. I would also move, delete events and etc.

I would have my email app read my emails (text to speech). I also write emails (dictate).

Same as the above for WhatsApp and other messaging apps.

I would use maps, music, even sometimes observe cameras from my app.

YouTube for sure.

On long trips I would play TV from my TV app. I would not watch it, but would listen to shows, news on TV.

 

[stargate125645]

For me navigation and playing music would be the most important uses cases. Can you tell me what you would be yours?

Also other people reading this, what would be your main reason to use a phone mirror app? Just to give me some clue what is important to have working.

My understanding is that the only audio you cannot capture and send to the head unit is voice navigation at this point, correct? Did I misinterpret that?

I would use AAU like my phone for all purposes (texting, email, phone calls, TV, videos, movies, music, navigation), but I don't actually use the voice portion of navigation - I just watch the screen and read. (I know a lot of people like that, actually.) So not hearing the voice during navigation is not even close to an issue for me. But, it would be nice to be able to make sure regular AA can still be used in the off chance that I would need voice information, hence my comment about switching being possible before starting the car.

If my above-stated understanding of the audio that isn't transferred is incorrect, then I would need a rooted phone. I would still purchase the app; however, I would have a secondary phone that I would root - I don't have time to keep up with all the updates necessary for a primary phone to be rooted.

Having a version of this app that doesn't require rooting would be the strong preference for me, even if a few features are missing. I'm not sure what all it would take for you to have a rooted and unrooted version, so I'm not sure if that's an option. Just one version is a huge amount of work I'm sure.

 

[micfogas]

The AVH-X2650BT has AppRadio USB and is not supported.

Hi. I know this is a really old post and my radio is outdated, but I've always used pioneer head units because, well, they are built well and last year's beyond their release periods. I've been using them since the first OLED displays nearly 20 years ago? Anyway..

I happen to have an AVH-X5800BHS which is AppRadio One via USB and, as you mentioned, not supported. I've tried finding some resources to use the AppRadio One feature (I never got it working even when it was brand new), but I haven't been able to find any.

If you don't mind a couple minutes of your time, would you mind giving me a rundown of the technical limitations that prevent something like your app from working on the USB models? It doesn't need to be ELI5 style, my technical knowledge is fairly advanced. I'm only asking you because of your specific expertise with the AppRadio software itself and I'm guessing you would have supported the USB version if it was doable without investing more time in it than it's worth. I haven't come across anyone else who has put time into it and shared what they learned, so I figured it's worth asking at least. I'm going to guess they used a proprietary protocol instead of standardized.

After I get my sound system finished (I only now decided to finally build it out), I plan to upgrade to a pioneer DMH series or something. Unless I decide to just build out the electronics and drop in a touch screen connected to an RPi.

Anyway thanks in advance either way.

 

[Area51©]

If you don't mind a couple minutes of your time, would you mind giving me a rundown of the technical limitations that prevent something like your app from working on the USB models? It doesn't need to be ELI5 style, my technical knowledge is fairly advanced. I'm only asking you because of your specific expertise with the AppRadio software itself and I'm guessing you would have supported the USB version if it was doable without investing more time in it than it's worth. I haven't come across anyone else who has put time into it and shared what they learned, so I figured it's worth asking at least. I'm going to guess they used a proprietary protocol instead of standardized.

To explain takes a bit more than a few minutes but ok. The supported head units get the phone's video via HDMI input. Touch data and so on goes back via Bluetooth RFCOMM. This is an emulated RS-232 connection. This is relatively easy to reverse engineer. I say relatively because it was hard enough to reverse engineer a binary serial protocol without having any source code.

AppRadio One uses USB for everything. This means that video from the phone is streamed via USB. Audio as well. Touch data and so on goes back via USB. In the app some library from a company called Abaltatech is used for this. The protocol is completely proprietary. At the time I was looking into this I was not familiar with streaming video. Also it's quite hard to even spy on USB traffic. It requires expensive equipment to do so. So I would say it's a magnitude more complicated than the Bluetooth protocol. I tried for a while to modify the Pioneer app but gave up on that as well.

Recently I worked on implementing the Android Auto protocol for a new app. AA works via USB too. This was easier as the protocol was reverse engineered by other people already. However this is also not 100% clear as there are different version of the protocol. I have a working prototype but there's one catch. Because of limitations Google put in Android it's not possible to capture system audio and transfer it to the head unit. I can make it work but that requires a rooted phone. I wanted to make it work without root so I am stuck there.

 

[EvilDragon17]

Recently I worked on implementing the Android Auto protocol for a new app. AA works via USB too. This was easier as the protocol was reverse engineered by other people already. However this is also not 100% clear as there are different version of the protocol. I have a working prototype but there's one catch. Because of limitations Google put in Android it's not possible to capture system audio and transfer it to the head unit. I can make it work but that requires a rooted phone. I wanted to make it work without root so I am stuck there.

Hm, how about a version that has optional root for system audio?
Some users don't need audio but just want to display some apps in their car which don't need audio?

And if you have root, you can use system audio.

Another idea: Most cars have an audio source selection so you can use navigation and listen to radio at the same time. Would it be possible to use Bluetooth to transfer the audio from the phone to the head unit?
Using that workaround it should be possible to transfer video via USB and audio via Bluetooth without the need of root.

 

[stargate125645]

Hm, how about a version that has optional root for system audio?
Some users don't need audio but just want to display some apps in their car which don't need audio?

And if you have root, you can use system audio.

Another idea: Most cars have an audio source selection so you can use navigation and listen to radio at the same time. Would it be possible to use Bluetooth to transfer the audio from the phone to the head unit?
Using that workaround it should be possible to transfer video via USB and audio via Bluetooth without the need of root.

If you can't capture the audio, I don't think it matters what method you use to stream it.

 

[EvilDragon17]

If you can't capture the audio, I don't think it matters what method you use to stream it.

Oh, you can't GRAB the internal audio at all... I thought you couldn't just route it to the AA USB protocol. All right, that will cause a problem.

My guess is that Google did that to prevent apps from recording anything that happens on your phone.

 

[Area51©]

Oh, you can't GRAB the internal audio at all... I thought you couldn't just route it to the AA USB protocol. All right, that will cause a problem.

My guess is that Google did that to prevent apps from recording anything that happens on your phone.

Yes, that's the issue.

Currently I think there's the following options:
1) It's possible to grab the audio when you have root.

2) Also you can always connect a Bluetooth audio device. So a device that can act as a Bluetooth device and then stream it back via wifi would be a possibility. That device could connect to the phone when it has it's hotspot enabled.
A possible implementation could be done with a Raspberry Pi Pico W microcontroller. It has wifi and Bluetooth but the Bluetooth is not enabled yet. But they are working on that.

3) I found that you can also route audio to a cheap USB audio device. You can then record the audio from the input if you loop it back. However those cheap USB audio devices only have mono audio input.
I think it would be possible to use a Raspberry Pi Pico microcontroller. You can implement all kind of USB devices with it. It took a brief look at it and a stereo audio loopback device could be done.

 

[EvilDragon17]

Yes, that's the issue.

Currently I think there's the following options:
1) It's possible to grab the audio when you have root.

2) Also you can always connect a Bluetooth audio device. So a device that can act as a Bluetooth device and then stream it back via wifi would be a possibility. That device could connect to the phone when it has it's hotspot enabled.
A possible implementation could be done with a Raspberry Pi Pico W microcontroller. It has wifi and Bluetooth but the Bluetooth is not enabled yet. But they are working on that.

3) I found that you can also route audio to a cheap USB audio device. You can then record the audio from the input if you loop it back. However those cheap USB audio devices only have mono audio input.
I think it would be possible to use a Raspberry Pi Pico microcontroller. You can implement all kind of USB devices with it. It took a brief look at it and a stereo audio loopback device could be done.

Hm, but thinking about it a bit more is audio grabbing really needed?

If I'm correct, grabbing audio is needed if you want to transfer all audio via the AA USB protocol.
So yes, for a proper and easy audio / video transfer to the car, audio grabbing would be needed.

However, if you ONLY transfer the video stream via AA USB and the user simply connects the smartphone via Bluetooth to the car, then why would audio grabbing be needed? Android would play ALL system audio via Bluetooth.

I once had the problem, that for some reason, Android Audio didn't send any audio via the USB connection.
And that's when I used that method as workaround. I simply connected the phone via Bluetooth and that worked fine.

 

[Area51©]

Hm, but thinking about it a bit more is audio grabbing really needed?

If I'm correct, grabbing audio is needed if you want to transfer all audio via the AA USB protocol.
So yes, for a proper and easy audio / video transfer to the car, audio grabbing would be needed.

However, if you ONLY transfer the video stream via AA USB and the user simply connects the smartphone via Bluetooth to the car, then why would audio grabbing be needed? Android would play ALL system audio via Bluetooth.

I once had the problem, that for some reason, Android Audio didn't send any audio via the USB connection.
And that's when I used that method as workaround. I simply connected the phone via Bluetooth and that worked fine.

OK. If your entertainment system supports AA and Bluetooth audio at the same time then that's a valid workaround. However that doesn't mean that every head unit / entertainment system supports this. The only thing that is sure that every system supports audio via the AA USB protocol.

 

[EvilDragon17]

OK. If your entertainment system supports AA and Bluetooth audio at the same time then that's a valid workaround. However that doesn't mean that every head unit / entertainment system supports this. The only thing that is sure that every system supports audio via the AA USB protocol.

Yes, it actually does that. A lot of people listen to normal radio, for example, but still need to get listen to the navigation from Android Auto. So both audio sources are mixed together.

And - at least in my car - Bluetooth is just another audio source like CD or Radio, so it can always be played at the same time as Android Auto.

I can imagine that most systems do it similar, they just use Android Auto as an overlay for both audio and video but still have their normal audio sources available.
Otherwise the only way to listen to music would be if the smartphone would play audio as well.