Changes for use with triggerhappy

README.md

@@ -1,16 +1,18 @@
 # raspi2png
 
-Utility to take a snapshot of the raspberry pi screen and save it as a PNG file
+Utility to take a snapshot of the raspberry pi screen and save it as a PNG file. Works with all Raspberry Pi boards.
 
-    Usage: raspi2png [--pngname name] [--width <width>] [--height <height>] [--compression <level>] [--delay <delay>] [--display <number>] [--stdout] [--help]
+    Usage: raspi2png [--pngname name] [--width <width>] [--height <height>] [--compression <level>] [--delay <delay>] [--display <number>] [--stdout] [--version] [--help]
 
     --pngname,-p - name of png file to create (default is snapshot.png)
     --height,-h - image height (default is screen height)
     --width,-w - image width (default is screen width)
     --compression,-c - PNG compression level (0 - 9)
     --delay,-d - delay in seconds (default 0)
     --display,-D - Raspberry Pi display number (default 0)
-	--stdout,-s - write file to stdout
+    --stdout,-s - write file to stdout
+    --savepath,-a - save path
+    --version,-v - print version number
     --help,-H - print this usage information
 
 ## Simple Install
@@ -21,9 +23,56 @@ curl -sL https://raw.githubusercontent.com/AndrewFromMelbourne/raspi2png/master/
 
 ## Manual Building
 
-You will need to install libpng before you build the program. On Raspbian
+You will need to install libpng before you build the program. On Raspbian / Raspberry Pi OS execute  
+``sudo apt-get install libpng-dev``  
+Then just type 'make' and 'make install' in the raspi2png directory you cloned from github.
 
-sudo apt-get install libpng12-dev
+## Execute with print key (triggerhappy)
 
-Then just type 'make' in the raspi2png directory you cloned from github.
+create configuration file '/etc/triggerhappy/triggers.d/printscr.conf':
+```
+KEY_SYSRQ	1	/usr/bin/raspi2png -a /home/pi/snapshot
+```
+execute following commands:
+```
+mkdir /home/pi/snapshot
+chmod g+w /home/pi/snapshot 
+sudo chown nobody /home/pi/snapshot
+sudo adduser nobody video
+sudo service triggerhappy restart
+```
+
+### Hardware GPIO input for print key (BCM26 active low)
+
+Command-line:
+```
+sudo dtoverlay gpio-key gpio=26 keycode=99 label="KEY_SYSRQ" gpio_pull=2
+```
+config.txt:
+```
+dtoverlay=gpio-key,gpio=26,keycode=99,label="KEY_SYSRQ",gpio_pull=2
+```
+
+
+## Benchmark
+
+raspi2png 1.1, 720p screen, Raspberry Pi 3 B, RAM-disk
+
+| compression | seconds | size (KiB) |
+|:-:|:----:|-----:|
+| 0 | 0,23 | 2705 | 
+| 1 | 0,42 |  676 |
+| **2** | 0,42 |  654 |
+| 3 | 0,53 |  624 |
+| 4 | 0,57 |  606 |
+| 5 | 0,71 |  593 |
+| 6 | 1,10 |  575 |
+| 7 | 1,46 |  569 |
+| 8 | 3,04 |  564 |
+| 9 | 5,30 |  560 |
+
+optipng size:  ~553 KiB  
+
+
+![Screenshot](https://github.com/GrazerComputerClub/raspi2png/raw/master/screenshot.png)
 

raspi2png.c

@@ -36,7 +36,8 @@
 #include <string.h>
 #include <unistd.h>
 #include <zlib.h>
-
+#include <time.h>
+#include <sys/stat.h>
 #include "bcm_host.h"
 
 //-----------------------------------------------------------------------
@@ -47,9 +48,14 @@
 
 //-----------------------------------------------------------------------
 
+#define VERSION "1.1"
 #define DEFAULT_DELAY 0
 #define DEFAULT_DISPLAY_NUMBER 0
-#define DEFAULT_NAME "snapshot.png"
+#define DEFAULT_PNG_COMPRESSION 2
+#define DEFAULT_NAME_START "snapshot"
+#define DEFAULT_NAME DEFAULT_NAME_START ".png"
+#define MAX_NAME_SIZE 50
+
 
 //-----------------------------------------------------------------------
 
@@ -60,11 +66,15 @@ const char* program = NULL;
 void
 usage(void)
 {
+    fprintf(stderr, "%s (%s)\n", program, VERSION);
+    fprintf(stderr, "Utility to take a snapshot of the raspberry pi screen and save it as a PNG file\n\n");
+
     fprintf(stderr, "Usage: %s [--pngname name]", program);
     fprintf(stderr, " [--width <width>] [--height <height>]");
     fprintf(stderr, " [--compression <level>]");
     fprintf(stderr, " [--delay <delay>] [--display <number>]");
-    fprintf(stderr, " [--stdout] [--help]\n");
+    fprintf(stderr, " [--stdout] [--savepath path]");
+    fprintf(stderr, " [--version] [--help]\n");
 
     fprintf(stderr, "\n");
 
@@ -88,12 +98,19 @@ usage(void)
 
     fprintf(stderr, "    --stdout,-s - write file to stdout\n");
 
+    fprintf(stderr, "    --savepath,-a - save path\n");
+
+    fprintf(stderr, "    --version,-v - print version number\n");
+
     fprintf(stderr, "    --help,-H - print this usage information\n");
 
     fprintf(stderr, "\n");
 }
 
-
+bool file_exists(char *filename) {
+  struct stat FileStat;
+  return (stat(filename, &FileStat) == 0);
+}
 //-----------------------------------------------------------------------
 
 int
@@ -104,11 +121,13 @@ main(
     int opt = 0;
 
     bool writeToStdout = false;
+    char pngNameWithTimestamp[MAX_NAME_SIZE+1];
     char *pngName = DEFAULT_NAME;
+    bool replace = false;
     int32_t requestedWidth = 0;
     int32_t requestedHeight = 0;
     uint32_t displayNumber = DEFAULT_DISPLAY_NUMBER;
-    int compression = Z_DEFAULT_COMPRESSION;
+    int compression = DEFAULT_PNG_COMPRESSION;
     int delay = DEFAULT_DELAY;
 
     VC_IMAGE_TYPE_T imageType = VC_IMAGE_RGBA32;
@@ -120,7 +139,7 @@ main(
 
     //-------------------------------------------------------------------
 
-    char *sopts = "c:d:D:Hh:p:w:s";
+    char *sopts = "c:d:D:Hh:p:w:s:a:v";
 
     struct option lopts[] =
     {
@@ -129,16 +148,23 @@ main(
         { "display", required_argument, NULL, 'D' },
         { "height", required_argument, NULL, 'h' },
         { "help", no_argument, NULL, 'H' },
+        { "version", no_argument, NULL, 'v' },
         { "pngname", required_argument, NULL, 'p' },
         { "width", required_argument, NULL, 'w' },
         { "stdout", no_argument, NULL, 's' },
+        { "savepath", required_argument, NULL, 'a' },
         { NULL, no_argument, NULL, 0 }
     };
 
     while ((opt = getopt_long(argc, argv, sopts, lopts, NULL)) != -1)
     {
         switch (opt)
         {
+        case 'a':
+
+            chdir(optarg);
+            break;
+
         case 'c':
 
             compression = atoi(optarg);
@@ -168,6 +194,7 @@ main(
         case 'p':
 
             pngName = optarg;
+            replace = true;
             break;
 
         case 'w':
@@ -180,6 +207,11 @@ main(
             writeToStdout = true;
             break;
 
+        case 'v':
+
+            fprintf(stderr, "%s (%s)\n", program, VERSION);
+            exit(EXIT_SUCCESS);
+
         case 'H':
         default:
 
@@ -522,8 +554,21 @@ main(
     }
     else
     {
-        pngfp = fopen(pngName, "wb");
+        if (!replace && file_exists(pngName))
+        {
+          time_t rawtime;
+          struct tm *ltime;
+          time(&rawtime);
+          ltime = localtime(&rawtime);
+          int nLen = strlen(DEFAULT_NAME_START);
+
+          strcpy(pngNameWithTimestamp, DEFAULT_NAME_START);
+          strftime(&pngNameWithTimestamp[nLen], MAX_NAME_SIZE-nLen,
+           "_%Y%m%d-%H%M%S.png",ltime);
+          pngName = pngNameWithTimestamp;
+        }
 
+        pngfp = fopen(pngName, "wb");
         if (pngfp == NULL)
         {
             fprintf(stderr,