screencap.cpp revision 9afc7b02facf4918d3033ebb4548b76a59b1373c 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <errno.h>
18#include <unistd.h>
19#include <stdio.h>
20#include <fcntl.h>
21
22#include <linux/fb.h>
23#include <sys/ioctl.h>
24#include <sys/mman.h>
25
26#include <binder/IMemory.h>
27#include <surfaceflinger/SurfaceComposerClient.h>
28
29#include <SkImageEncoder.h>
30#include <SkBitmap.h>
31#include <SkStream.h>
32
33using namespace android;
34
35static void usage(const char* pname)
36{
37    fprintf(stderr,
38            "usage: %s [-hp] [FILENAME]\n"
39            "   -h: this message\n"
40            "   -p: save the file as a png.\n"
41            "If FILENAME ends with .png it will be saved as a png.\n"
42            "If FILENAME is not given, the results will be printed to stdout.\n",
43            pname
44    );
45}
46
47static SkBitmap::Config flinger2skia(PixelFormat f)
48{
49    switch (f) {
50        case PIXEL_FORMAT_A_8:
51        case PIXEL_FORMAT_L_8:
52            return SkBitmap::kA8_Config;
53        case PIXEL_FORMAT_RGB_565:
54            return SkBitmap::kRGB_565_Config;
55        case PIXEL_FORMAT_RGBA_4444:
56            return SkBitmap::kARGB_4444_Config;
57        default:
58            return SkBitmap::kARGB_8888_Config;
59    }
60}
61
62static status_t vinfoToPixelFormat(const fb_var_screeninfo& vinfo,
63        uint32_t* bytespp, uint32_t* f)
64{
65
66    switch (vinfo.bits_per_pixel) {
67        case 16:
68            *f = PIXEL_FORMAT_RGB_565;
69            *bytespp = 2;
70            break;
71        case 24:
72            *f = PIXEL_FORMAT_RGB_888;
73            *bytespp = 3;
74            break;
75        case 32:
76            // TODO: do better decoding of vinfo here
77            *f = PIXEL_FORMAT_RGBX_8888;
78            *bytespp = 4;
79            break;
80        default:
81            return BAD_VALUE;
82    }
83    return NO_ERROR;
84}
85
86int main(int argc, char** argv)
87{
88    const char* pname = argv[0];
89    bool png = false;
90    int c;
91    while ((c = getopt(argc, argv, "ph")) != -1) {
92        switch (c) {
93            case 'p':
94                png = true;
95                break;
96            case '?':
97            case 'h':
98                usage(pname);
99                return 1;
100        }
101    }
102    argc -= optind;
103    argv += optind;
104
105    int fd = -1;
106    if (argc == 0) {
107        fd = dup(STDOUT_FILENO);
108    } else if (argc == 1) {
109        const char* fn = argv[0];
110        fd = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0664);
111        if (fd == -1) {
112            fprintf(stderr, "Error opening file: %s (%s)\n", fn, strerror(errno));
113            return 1;
114        }
115        const int len = strlen(fn);
116        if (len >= 4 && 0 == strcmp(fn+len-4, ".png")) {
117            png = true;
118        }
119    }
120
121    if (fd == -1) {
122        usage(pname);
123        return 1;
124    }
125
126    void const* mapbase = MAP_FAILED;
127    ssize_t mapsize = -1;
128
129    void const* base = 0;
130    uint32_t w, h, f;
131    size_t size = 0;
132
133    ScreenshotClient screenshot;
134    if (screenshot.update() == NO_ERROR) {
135        base = screenshot.getPixels();
136        w = screenshot.getWidth();
137        h = screenshot.getHeight();
138        f = screenshot.getFormat();
139        size = screenshot.getSize();
140    } else {
141        const char* fbpath = "/dev/graphics/fb0";
142        int fb = open(fbpath, O_RDONLY);
143        if (fb >= 0) {
144            struct fb_var_screeninfo vinfo;
145            if (ioctl(fb, FBIOGET_VSCREENINFO, &vinfo) == 0) {
146                uint32_t bytespp;
147                if (vinfoToPixelFormat(vinfo, &bytespp, &f) == NO_ERROR) {
148                    size_t offset = (vinfo.xoffset + vinfo.yoffset*vinfo.xres) * bytespp;
149                    w = vinfo.xres;
150                    h = vinfo.yres;
151                    size = w*h*bytespp;
152                    mapsize = offset + size;
153                    mapbase = mmap(0, mapsize, PROT_READ, MAP_PRIVATE, fb, 0);
154                    if (mapbase != MAP_FAILED) {
155                        base = (void const *)((char const *)mapbase + offset);
156                    }
157                }
158            }
159            close(fb);
160        }
161    }
162
163    if (base) {
164        if (png) {
165            SkBitmap b;
166            b.setConfig(flinger2skia(f), w, h);
167            b.setPixels((void*)base);
168            SkDynamicMemoryWStream stream;
169            SkImageEncoder::EncodeStream(&stream, b,
170                    SkImageEncoder::kPNG_Type, SkImageEncoder::kDefaultQuality);
171            write(fd, stream.getStream(), stream.getOffset());
172        } else {
173            write(fd, &w, 4);
174            write(fd, &h, 4);
175            write(fd, &f, 4);
176            write(fd, base, size);
177        }
178    }
179    close(fd);
180    if (mapbase != MAP_FAILED) {
181        munmap((void *)mapbase, mapsize);
182    }
183    return 0;
184}
185