Very interesting... I'll have to look into whether that would be a viable way of grabbing an image or not! Would probably be more along the lines of native android development for specific devices, but maybe that could be an option,
I think it will need root but for what I know is pretty standard, at least in older android version it worked on most of devices, there is an old tool to test it from adb if you don't want to code it, https://forum.xda-developers.com/showthread.php?t=2233751
Another little update, I've tried to grab directly from the frame buffer, /dev/graphics/fb0, unfortunately the nvidia shield tv reboots it self when touching it, either reading or writing it, I think they are using a custom framebuffer or it is some sort of protection but maybe on other devices it could work (also, I'm not expert and I could have caused it due to my lack of experience )
I used magisk to have a systemless mod, this way my system partition is clean and a future update will only disable the mod with no mix of files or bootloops
Talking about taking screenshot in protected apps, I was trying this app https://play.google.com/store/…apps.screenshoteasy&hl=it on a modded galaxy s5 and I get to to take screenshot from netflix videos at 540p but I can't go further for the lack of l1 certification (i'm on lineage os, not stock rom) and I can't test it on nvidia shield tv for the lack of way to trigger the screenshot command (the custom command of the app, the standard one is triggable with a keyboard).
I've also tried the "liboemcrypto disabler" magisk module but netflix stopped working and amazon prime video was playing (maybe was low resolution but I didn't care much of it at this point, I was just exploring) but not working with the grabber, so no luck here.
I'm afraid that as abrenoch was saying the protection is running on a hw level and it's very likely that is not breakable, you can just run it or disable it but not trick it, at least not with my skills.
It's a shame that my bravia xe9005 has no root and I don't want to risk so much, I think that the protection running on hdmi input is much more weak than the one running on ondemand apps like netflix, maybe the "disable secure flag" module could trick it and completely solve the problem
Sure here is what I did, it may be a little different with the 2017 shield:
1) download the developer image from nvidia site https://developer.nvidia.com/shield-developer-os-images
2) extract the boot.img from the zip file
3) transfer it on a device with magisk installed (it's the only way for what I know, using other way can cause bootloop)
4) open magisk and select install, select install again, choose patch boot image file, select your boot.img downloaded from nvidia site, at the end you will have a patched_boot.img file
5) transfer it back to your computer
6) install minimal ADB if you don't have it and enable developer settings on your nvidia shield, enable also usb debug from the developer menu
7) connect a pc to your shield via usb cable (standard usb to mini usb for 2015 ) and reboot your shield in fastboot mode with the command "adb reboot bootloader"
unlock your bootloader with the command "fastboot oem unlock", please note that it will factory reset your nvidia shield and it will take like 5 minutes
9) test your boot image with the command "fastboot boot patched_boot.img" if it works go back in bootloader mode with "adb reboot bootloader" and flash it with "fastboot flash boot patched_boot.img"
10) now you should have magisk installed but you might need sideload launcher to see the magisk manager https://play.google.com/store/…tv.sideloadlauncher&hl=it
11) install xposed installer from this apk https://basketbuild.com/filedl…nstaller_3.1.5-Magisk.apk you can push it with adb using the command "adb install XposedInstaller_3.1.5-Magisk.apk"
12) open magisk manager, go to downloads and search for xposed, the versione we need with Oreo is sdk26 (version 90 beta 3), download it and enable it, then reboot
13) now install this https://dl-xda.xposed.info/mod…eflagsecure_v3_c38d39.apk you can side load it with "adb install fi.veetipaananen.android.disableflagsecure_v3_c38d39.apk"
14) open xposed go to modules and you should see DisableFlagSecure, enable it, now reboot
15) done
some notes:
- I tried to build a magisk module to disable flag secure with smali patcher but it didn't work
- I don't respond of any damage to your console, this is just what I did, not what you should do
- even after disabling flagsecure protected content can't be grabbed, maybe it will change in future but for now this will only enable grabber in netflix modded apk (but there is no HD) or in standard netflix menu but not in netflix video
- I installed a modded netflix apk https://forum.xda-developers.c…ahd-dolby-5-1-l1-t3535349 they say that it should work at 4k or at least 1080p but I think that something is changed because I can't get more than 480p, not ideal at all, I was just trying to understand if flag secure was the only limitation and it's not, but we are a step closer
- If you chromecast netflix from chrome to the shield you get 720p with grabbing enabled but I don't know if it was working before, if you cast from the app this will not work and the standard app will open and play the video
Hello, first of all, thank you for your great app, I have an Nvidia Shield tv 2015 and it works very well.
I've something to share, I tried to disable secure flag system wide, I managed to get there by unlocking the bootloader, downloading the boot.img fron the nvidia site, patching it with another phone with magisk installed (maybe there other ways but this seems to be the only one working for nvidia shield), flashed it to the shield through fastboot, installed magisk module for xposed framework api 26 (for oreo 8.0, other version will use other apis), xposed installer apk for magisk, and disable secure flag xposed module.
Now I'm allowed to take screenshot everywhere, and your screen grabber can grab at least the netflix menu (before it couldn't) but sadly the screenshot while playing netflix or amazon prime video are still black, the great think is that i can grab from the modded netflix apk from xda (https://forum.xda-developers.c…ahd-dolby-5-1-l1-t3535349)
I think it's worth some more investigation, I'm pretty sure that once disabled the secure flag the problem still remaining is widevine L1 since the L3 version works, but I think I can't do much more with my skill level
