Support has ended, due to the possibility of pixel formats changing from each recovery update you receive.
But I did make a better Recovery Screenshot that handles this problem, and it can be found here or below.
It's no big secret around XDA that you can use the program FFmpeg to convert your raw framebuffer file into a normal image file. I've found the values for the Nexus 5 and made a batch script that incorporates the programs adb, and ffmpeg; to save screenshots to your computer. I don't have a Nexus 5, but thanks to an XDA user, @ikslawlok, who posted his raw framebuffer from TWRP 184.108.40.206 on another website, I was able to get it working. Also thanks to @rootSU for testing in Philz, a CWM based recovery. This should work on all versions of Windows. I have only tested in Windows 7 personally. The process, as far as using ffmpeg and adb, used here is also possible in Linux. Some versions of ffmpeg for Linux are antiquated, hence there isn't really a write one script; work for all.
Why would anyone use this or do this?
Most people, that probably includes you reading this, have actually no use for it, nor can you think of a reason too. The uses of this are limited to people that write tutorials, custom recovery themes, and the rare event that you have an anomaly in your recovery and you can't describe it.
I owe a big thanks to @Whiskey103 with his work in this thread over in the HTC One forum.
You have to have the adb drivers installed before you can do anything. Go here for more information.
This rar file contains the programs adb and ffmpeg. This 32-bit version of ffmpeg is one of the newest versions available on their downloads page. You must have adb.exe, ffmpeg.exe, and the two dll files for adb in the same directory as the batch file. The easiest thing to do is just extract the rar to a new directory, then run the file named "RUNrsn511.bat" The screenshots you capture will be saved in the same folder that you unzipped everything in as 'timestamp'.png
Thank you @weihan1102 for helping me test and providing your framebuffer from the modified version of TWRP for multirom!
Download Recovery Screenshot v1.1
If you have already downloaded the original version, and wish to update with support for the modified twrp for multirom without downloading the whole new rar, then hit the button below.
An easier way, I think, is to click show content below and click anywhere in the box. Hit Ctrl+A to select everything, hit Ctrl+C to copy it to the clipboard. Then right click on your original RUNrs.bat file, and select edit. Click in that screen anywhere, hit Ctrl+A to select everything in there, then Ctrl+V to paste the new batch script into RUNrs.bat.
@ECHO OFF CLS TITLE Recovery Screenshot v1.1 MODE CON:COLS=54 LINES=40 COLOR 0B SET TS=0 SET "ffshowb=-hide_banner" SET "ffdebug=-loglevel fatal" IF "%~1"=="-d" ( REM @ECHO ON SET "ffdebug=-loglevel debug" SET "ffshowb=%" MODE CON:COLS=140 LINES=250 COLOR 07 ECHO __________________________________________________________________ ECHO DEBUG INFO ECHO __________________________________________________________________ ) :START ECHO[ ECHO ______________________________________________________ ECHO This will pull a screenshot from your Nexus 5 and ECHO save it to the directory that you ran this bat ECHO file in. Connect USB ^& reboot into your recovery. ECHO ______________________________________________________ ECHO Thanks to Whiskey103 for the idea!! ECHO Written by makers_mark ECHO ______________________________________________________ IF NOT EXIST ffmpeg.exe GOTO NOFILES IF NOT EXIST adb.exe GOTO NOFILES ADB kill-server -d >nul 2>&1 IF %TS%=="NOGOOD" GOTO SKIPPEDthatPause ECHO Press 1 or 2 ECHO 1 - Save a screenshot using multirom twrp recovery ECHO 2 - Save a screenshot using other recoveries ECHO ______________________________________________________ CHOICE /C:12 >nul IF ERRORLEVEL 1 SET K=1 IF ERRORLEVEL 2 SET K=2 IF %K%==1 SET "pixfmt=-pix_fmt rgb565" IF %K%==2 SET "pixfmt=-pix_fmt rgb0" :SKIPPEDthatPause ECHO[ ECHO Pulling framebuffer from /dev/graphics/fb0 adb pull /dev/graphics/fb0 frmbfr >nul IF ERRORLEVEL 1 (cls SET TS="NOGOOD" ECHO ______________________________________________________ ECHO Adb is not properly connected. ECHO Try "Safely Removing" your N5 from your computer ECHO Then unplug your usb cable, and reinsert it. ECHO ______________________________________________________ ECHO[ ECHO[ ECHO Press any key to try again. ECHO[ ECHO[ PAUSE >nul CLS GOTO START ) SET TS=%DATE:/=%_%TIME::=_% SET TS=%TS:.=% SET TS=%TS: =%.png FFMPEG %ffdebug% %ffshowb% -f rawvideo -vcodec rawvideo %pixfmt% -s 1088x1920 -i frmbfr -vf crop=1080:1920:0:0 -y %TS% IF NOT EXIST %TS% GOTO ERRNE DEL frmbfr >nul ECHO ______________________________________________________ ECHO Screenshot saved as %TS% ECHO ______________________________________________________ ECHO Press 1 or 2 ECHO 1 - Save another screenshot ECHO 2 - Exit ECHO ______________________________________________________ CHOICE /C:12 >nul IF ERRORLEVEL 1 SET K=1 IF ERRORLEVEL 2 SET K=2 IF %K%==1 GOTO SKIPPEDthatPause IF %K%==2 GOTO FINISH :NOFILES CLS ECHO The directory that you are running this script in is: ECHO %~dp0 ECHO[ ECHO You must run this script in the same directory as ECHO adb.exe and ffmpeg.exe. Press any key to exit PAUSE >nul EXIT :ERRNE CLS MODE CON:COLS=108 LINES=200 COLOR 07 FFMPEG -loglevel debug -f rawvideo -vcodec rawvideo %pixfmt% -s 1088x1920 -i frmbfr -vf crop=1080:1920:0:0 -y %TS% ECHO ____________________________________________________________________________________________________________ ECHO There was a problem converting the framebuffer to a png file. ECHO[ ECHO To capture the screen of the cmd window, hold down the alt key and press PrtSc on your keyboard. This ECHO will save an image of the current window in memory on your clipboard. Then open paint or photoshop or ECHO whatever program you use and hit ctrl+N to open a new file, then ctrl+V to paste an image. Save it and ECHO please message me it or post in the XDA forum thread. ECHO[ ECHO[ ECHO If you got to this screen and are not using a Nexus 5, congratulations for successfully pulling the ECHO framebuffer. To figure out the resolution to use, try adding 4,8, or 16 to your native width to make it ECHO evenly divisible by 32. Example resolution is 1080x1920..1080^/32^=33.75 ^< not right, so try 1088^/32^=34 ^< good ECHO Only worry about width (left to right), height is stored orderly in memory. ECHO[ ECHO To see a list of all of the pix_fmts supported by ffmpeg, run ffmpeg -pix_fmts ECHO[ ECHO Press 1 or 2 ECHO 1 - Show available pixel formats ECHO 2 - Exit CHOICE /C:12 IF ERRORLEVEL 1 SET K=1 IF ERRORLEVEL 2 SET K=2 IF %K%==1 (cls MODE CON:COLS=52 LINES=200 ffmpeg -hide_banner -pix_fmts pause GOTO FINISH) IF %K%==2 GOTO FINISH :FINISH ADB kill-server -d EXIT
I have more screenshots at my 2013 Nexus 7 thread.