1 #include <stdlib.h> 2 #include <stdio.h> 3 #include <unistd.h> 4 #include <string.h> 5 #include <fcntl.h> 6 #include <errno.h> 7 8 #include <linux/fb.h> 9 10 #include <zlib.h> 11 #include <libpng/png.h> 12 13 #include "private/android_filesystem_config.h" 14 15 #define LOG_TAG "screenshot" 16 #include <utils/Log.h> 17 18 void take_screenshot(FILE *fb_in, FILE *fb_out) { 19 int fb; 20 char imgbuf[0x10000]; 21 struct fb_var_screeninfo vinfo; 22 png_structp png; 23 png_infop info; 24 unsigned int r,c,rowlen; 25 unsigned int bytespp,offset; 26 27 fb = fileno(fb_in); 28 if(fb < 0) { 29 ALOGE("failed to open framebuffer\n"); 30 return; 31 } 32 fb_in = fdopen(fb, "r"); 33 34 if(ioctl(fb, FBIOGET_VSCREENINFO, &vinfo) < 0) { 35 ALOGE("failed to get framebuffer info\n"); 36 return; 37 } 38 fcntl(fb, F_SETFD, FD_CLOEXEC); 39 40 png = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); 41 if (png == NULL) { 42 ALOGE("failed png_create_write_struct\n"); 43 fclose(fb_in); 44 return; 45 } 46 47 png_init_io(png, fb_out); 48 info = png_create_info_struct(png); 49 if (info == NULL) { 50 ALOGE("failed png_create_info_struct\n"); 51 png_destroy_write_struct(&png, NULL); 52 fclose(fb_in); 53 return; 54 } 55 if (setjmp(png_jmpbuf(png))) { 56 ALOGE("failed png setjmp\n"); 57 png_destroy_write_struct(&png, NULL); 58 fclose(fb_in); 59 return; 60 } 61 62 bytespp = vinfo.bits_per_pixel / 8; 63 png_set_IHDR(png, info, 64 vinfo.xres, vinfo.yres, vinfo.bits_per_pixel / 4, 65 PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE, 66 PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); 67 png_write_info(png, info); 68 69 rowlen=vinfo.xres * bytespp; 70 if (rowlen > sizeof(imgbuf)) { 71 ALOGE("crazy rowlen: %d\n", rowlen); 72 png_destroy_write_struct(&png, NULL); 73 fclose(fb_in); 74 return; 75 } 76 77 offset = vinfo.xoffset * bytespp + vinfo.xres * vinfo.yoffset * bytespp; 78 fseek(fb_in, offset, SEEK_SET); 79 80 for(r=0; r<vinfo.yres; r++) { 81 int len = fread(imgbuf, 1, rowlen, fb_in); 82 if (len <= 0) break; 83 png_write_row(png, (png_bytep)imgbuf); 84 } 85 86 png_write_end(png, info); 87 fclose(fb_in); 88 png_destroy_write_struct(&png, NULL); 89 } 90 91 void fork_sound(const char* path) { 92 pid_t pid = fork(); 93 if (pid == 0) { 94 execl("/system/bin/stagefright", "stagefright", "-o", "-a", path, NULL); 95 } 96 } 97 98 void usage() { 99 fprintf(stderr, 100 "usage: screenshot [-s soundfile] filename.png\n" 101 " -s: play a sound effect to signal success\n" 102 " -i: autoincrement to avoid overwriting filename.png\n" 103 ); 104 } 105 106 int main(int argc, char**argv) { 107 FILE *png = NULL; 108 FILE *fb_in = NULL; 109 char outfile[PATH_MAX] = ""; 110 111 char * soundfile = NULL; 112 int do_increment = 0; 113 114 int c; 115 while ((c = getopt(argc, argv, "s:i")) != -1) { 116 switch (c) { 117 case 's': soundfile = optarg; break; 118 case 'i': do_increment = 1; break; 119 case '?': 120 case 'h': 121 usage(); exit(1); 122 } 123 } 124 argc -= optind; 125 argv += optind; 126 127 if (argc < 1) { 128 usage(); exit(1); 129 } 130 131 strlcpy(outfile, argv[0], PATH_MAX); 132 if (do_increment) { 133 struct stat st; 134 char base[PATH_MAX] = ""; 135 int i = 0; 136 while (stat(outfile, &st) == 0) { 137 if (!base[0]) { 138 char *p = strrchr(outfile, '.'); 139 if (p) *p = '\0'; 140 strcpy(base, outfile); 141 } 142 snprintf(outfile, PATH_MAX, "%s-%d.png", base, ++i); 143 } 144 } 145 146 fb_in = fopen("/dev/graphics/fb0", "r"); 147 if (!fb_in) { 148 fprintf(stderr, "error: could not read framebuffer\n"); 149 exit(1); 150 } 151 152 /* switch to non-root user and group */ 153 gid_t groups[] = { AID_LOG, AID_SDCARD_RW }; 154 setgroups(sizeof(groups)/sizeof(groups[0]), groups); 155 setuid(AID_SHELL); 156 157 png = fopen(outfile, "w"); 158 if (!png) { 159 fprintf(stderr, "error: writing file %s: %s\n", 160 outfile, strerror(errno)); 161 exit(1); 162 } 163 164 take_screenshot(fb_in, png); 165 166 if (soundfile) { 167 fork_sound(soundfile); 168 } 169 170 exit(0); 171 } 172
