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最简单的基于FFmpeg的AVDevice例子文章列表：

最简单的基于FFmpeg的AVDevice例子（读取摄像头）

最简单的基于FFmpeg的AVDevice例子（屏幕录制）
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1. //Use gdigrab
2. AVDictionary* options = NULL;
3. //Set some options
4. //grabbing frame rate
5. //av_dict_set(&options,"framerate","5",0);
6. //The distance from the left edge of the screen or desktop
7. //av_dict_set(&options,"offset_x","20",0);
8. //The distance from the top edge of the screen or desktop
9. //av_dict_set(&options,"offset_y","40",0);
10. //Video frame size. The default is to capture the full screen
11. //av_dict_set(&options,"video_size","640x480",0);
12. AVInputFormat *ifmt=av_find_input_format("gdigrab");
13. if(avformat_open_input(&pFormatCtx,"desktop",ifmt,&options)!=0){
14. printf("Couldn't open input stream.（无法打开输入流）\n");
15. return -1;
16. }

1. AVInputFormat *ifmt=av_find_input_format("dshow");
2. if(avformat_open_input(&pFormatCtx,"video=screen-capture-recorder",ifmt,NULL)!=0){
3. printf("Couldn't open input stream.（无法打开输入流）\n");
4. return -1;
5. }

1. /**
2. * 最简单的基于FFmpeg的AVDevice例子（屏幕录制）
3. * Simplest FFmpeg Device (Screen Capture)
4. *
5. * 雷霄骅 Lei Xiaohua
6. * leixiaohua1020@126.com
7. * 中国传媒大学/数字电视技术
8. * Communication University of China / Digital TV Technology
9. * http://blog.csdn.net/leixiaohua1020
10. *
11. * 本程序实现了屏幕录制功能。可以录制并播放桌面数据。是基于FFmpeg
12. * 的libavdevice类库最简单的例子。通过该例子，可以学习FFmpeg中
13. * libavdevice类库的使用方法。
14. * 本程序在Windows下可以使用2种方式录制屏幕：
15. *  1.gdigrab: Win32下的基于GDI的屏幕录制设备。
16. *             抓取桌面的时候，输入URL为“desktop”。
17. *  2.dshow: 使用Directshow。注意需要安装额外的软件screen-capture-recorder
18. * 在Linux下可以使用x11grab录制屏幕。
19. * 在MacOS下可以使用avfoundation录制屏幕。
20. *
21. * This software capture screen of computer. It's the simplest example
22. * about usage of FFmpeg's libavdevice Library.
23. * It's suiltable for the beginner of FFmpeg.
24. * This software support 2 methods to capture screen in Microsoft Windows:
25. *  1.gdigrab: Win32 GDI-based screen capture device.
26. *             Input URL in avformat_open_input() is "desktop".
27. *  2.dshow: Use Directshow. Need to install screen-capture-recorder.
28. * It use x11grab to capture screen in Linux.
29. * It use avfoundation to capture screen in MacOS.
30. */
31. #include <stdio.h>
32. #define __STDC_CONSTANT_MACROS
33. #ifdef _WIN32
34. //Windows
35. extern "C"
36. {
37. #include "libavcodec/avcodec.h"
38. #include "libavformat/avformat.h"
39. #include "libswscale/swscale.h"
40. #include "libavdevice/avdevice.h"
41. #include "SDL/SDL.h"
42. };
43. #else
44. //Linux...
45. #ifdef __cplusplus
46. extern "C"
47. {
48. #endif
49. #include <libavcodec/avcodec.h>
50. #include <libavformat/avformat.h>
51. #include <libswscale/swscale.h>
52. #include <libavdevice/avdevice.h>
53. #include <SDL/SDL.h>
54. #ifdef __cplusplus
55. };
56. #endif
57. #endif
58. //Output YUV420P
59. #define OUTPUT_YUV420P 0
60. //'1' Use Dshow
61. //'0' Use GDIgrab
62. #define USE_DSHOW 0
63. //Refresh Event
64. #define SFM_REFRESH_EVENT  (SDL_USEREVENT + 1)
65. #define SFM_BREAK_EVENT  (SDL_USEREVENT + 2)
66. int thread_exit=0;
67. int sfp_refresh_thread(void *opaque)
68. {
69. thread_exit=0;
70. while (!thread_exit) {
71. SDL_Event event;
72. event.type = SFM_REFRESH_EVENT;
73. SDL_PushEvent(&event);
74. SDL_Delay(40);
75. }
76. thread_exit=0;
77. //Break
78. SDL_Event event;
79. event.type = SFM_BREAK_EVENT;
80. SDL_PushEvent(&event);
81. return 0;
82. }
83. //Show Dshow Device
84. void show_dshow_device(){
85. AVFormatContext *pFormatCtx = avformat_alloc_context();
86. AVDictionary* options = NULL;
87. av_dict_set(&options,"list_devices","true",0);
88. AVInputFormat *iformat = av_find_input_format("dshow");
89. printf("========Device Info=============\n");
90. avformat_open_input(&pFormatCtx,"video=dummy",iformat,&options);
91. printf("================================\n");
92. }
93. //Show AVFoundation Device
94. void show_avfoundation_device(){
95. AVFormatContext *pFormatCtx = avformat_alloc_context();
96. AVDictionary* options = NULL;
97. av_dict_set(&options,"list_devices","true",0);
98. AVInputFormat *iformat = av_find_input_format("avfoundation");
99. printf("==AVFoundation Device Info===\n");
100. avformat_open_input(&pFormatCtx,"",iformat,&options);
101. printf("=============================\n");
102. }
103. int main(int argc, char* argv[])
104. {
105. AVFormatContext *pFormatCtx;
106. int             i, videoindex;
107. AVCodecContext  *pCodecCtx;
108. AVCodec         *pCodec;
109. av_register_all();
110. avformat_network_init();
111. pFormatCtx = avformat_alloc_context();
112. //Open File
113. //char filepath[]="src01_480x272_22.h265";
114. //avformat_open_input(&pFormatCtx,filepath,NULL,NULL)
115. //Register Device
116. avdevice_register_all();
117. //Windows
118. #ifdef _WIN32
119. #if USE_DSHOW
120. //Use dshow
121. //
122. //Need to Install screen-capture-recorder
123. //screen-capture-recorder
124. //Website: http://sourceforge.net/projects/screencapturer/
125. //
126. AVInputFormat *ifmt=av_find_input_format("dshow");
127. if(avformat_open_input(&pFormatCtx,"video=screen-capture-recorder",ifmt,NULL)!=0){
128. printf("Couldn't open input stream.\n");
129. return -1;
130. }
131. #else
132. //Use gdigrab
133. AVDictionary* options = NULL;
134. //Set some options
135. //grabbing frame rate
136. //av_dict_set(&options,"framerate","5",0);
137. //The distance from the left edge of the screen or desktop
138. //av_dict_set(&options,"offset_x","20",0);
139. //The distance from the top edge of the screen or desktop
140. //av_dict_set(&options,"offset_y","40",0);
141. //Video frame size. The default is to capture the full screen
142. //av_dict_set(&options,"video_size","640x480",0);
143. AVInputFormat *ifmt=av_find_input_format("gdigrab");
144. if(avformat_open_input(&pFormatCtx,"desktop",ifmt,&options)!=0){
145. printf("Couldn't open input stream.\n");
146. return -1;
147. }
148. #endif
149. #elif defined linux
150. //Linux
151. AVDictionary* options = NULL;
152. //Set some options
153. //grabbing frame rate
154. //av_dict_set(&options,"framerate","5",0);
155. //Make the grabbed area follow the mouse
156. //av_dict_set(&options,"follow_mouse","centered",0);
157. //Video frame size. The default is to capture the full screen
158. //av_dict_set(&options,"video_size","640x480",0);
159. AVInputFormat *ifmt=av_find_input_format("x11grab");
160. //Grab at position 10,20
161. if(avformat_open_input(&pFormatCtx,":0.0+10,20",ifmt,&options)!=0){
162. printf("Couldn't open input stream.\n");
163. return -1;
164. }
165. #else
166. show_avfoundation_device();
167. //Mac
168. AVInputFormat *ifmt=av_find_input_format("avfoundation");
169. //Avfoundation
170. //[video]:[audio]
171. if(avformat_open_input(&pFormatCtx,"1",ifmt,NULL)!=0){
172. printf("Couldn't open input stream.\n");
173. return -1;
174. }
175. #endif
176. if(avformat_find_stream_info(pFormatCtx,NULL)<0)
177. {
178. printf("Couldn't find stream information.\n");
179. return -1;
180. }
181. videoindex=-1;
182. for(i=0; i<pFormatCtx->nb_streams; i++)
183. if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO)
184. {
185. videoindex=i;
186. break;
187. }
188. if(videoindex==-1)
189. {
190. printf("Didn't find a video stream.\n");
191. return -1;
192. }
193. pCodecCtx=pFormatCtx->streams[videoindex]->codec;
194. pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
195. if(pCodec==NULL)
196. {
197. printf("Codec not found.\n");
198. return -1;
199. }
200. if(avcodec_open2(pCodecCtx, pCodec,NULL)<0)
201. {
202. printf("Could not open codec.\n");
203. return -1;
204. }
205. AVFrame *pFrame,*pFrameYUV;
206. pFrame=av_frame_alloc();
207. pFrameYUV=av_frame_alloc();
208. //unsigned char *out_buffer=(unsigned char *)av_malloc(avpicture_get_size(AV_PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height));
209. //avpicture_fill((AVPicture *)pFrameYUV, out_buffer, AV_PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);
210. //SDL----------------------------
211. if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
212. printf( "Could not initialize SDL - %s\n", SDL_GetError());
213. return -1;
214. }
215. int screen_w=640,screen_h=360;
216. const SDL_VideoInfo *vi = SDL_GetVideoInfo();
217. //Half of the Desktop's width and height.
218. screen_w = vi->current_w/2;
219. screen_h = vi->current_h/2;
220. SDL_Surface *screen;
221. screen = SDL_SetVideoMode(screen_w, screen_h, 0,0);
222. if(!screen) {
223. printf("SDL: could not set video mode - exiting:%s\n",SDL_GetError());
224. return -1;
225. }
226. SDL_Overlay *bmp;
227. bmp = SDL_CreateYUVOverlay(pCodecCtx->width, pCodecCtx->height,SDL_YV12_OVERLAY, screen);
228. SDL_Rect rect;
229. rect.x = 0;
230. rect.y = 0;
231. rect.w = screen_w;
232. rect.h = screen_h;
233. //SDL End------------------------
234. int ret, got_picture;
235. AVPacket *packet=(AVPacket *)av_malloc(sizeof(AVPacket));
236. #if OUTPUT_YUV420P
237. FILE *fp_yuv=fopen("output.yuv","wb+");
238. #endif
239. struct SwsContext *img_convert_ctx;
240. img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, AV_PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);
241. //------------------------------
242. SDL_Thread *video_tid = SDL_CreateThread(sfp_refresh_thread,NULL);
243. //
244. SDL_WM_SetCaption("Simplest FFmpeg Grab Desktop",NULL);
245. //Event Loop
246. SDL_Event event;
247. for (;;) {
248. //Wait
249. SDL_WaitEvent(&event);
250. if(event.type==SFM_REFRESH_EVENT){
251. //------------------------------
252. if(av_read_frame(pFormatCtx, packet)>=0){
253. if(packet->stream_index==videoindex){
254. ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, packet);
255. if(ret < 0){
256. printf("Decode Error.\n");
257. return -1;
258. }
259. if(got_picture){
260. SDL_LockYUVOverlay(bmp);
261. pFrameYUV->data[0]=bmp->pixels[0];
262. pFrameYUV->data[1]=bmp->pixels[2];
263. pFrameYUV->data[2]=bmp->pixels[1];
264. pFrameYUV->linesize[0]=bmp->pitches[0];
265. pFrameYUV->linesize[1]=bmp->pitches[2];
266. pFrameYUV->linesize[2]=bmp->pitches[1];
267. sws_scale(img_convert_ctx, (const unsigned char* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameYUV->data, pFrameYUV->linesize);
268. #if OUTPUT_YUV420P
269. int y_size=pCodecCtx->width*pCodecCtx->height;
270. fwrite(pFrameYUV->data[0],1,y_size,fp_yuv);    //Y
271. fwrite(pFrameYUV->data[1],1,y_size/4,fp_yuv);  //U
272. fwrite(pFrameYUV->data[2],1,y_size/4,fp_yuv);  //V
273. #endif
274. SDL_UnlockYUVOverlay(bmp);
275. SDL_DisplayYUVOverlay(bmp, &rect);
276. }
277. }
278. av_free_packet(packet);
279. }else{
280. //Exit Thread
281. thread_exit=1;
282. }
283. }else if(event.type==SDL_QUIT){
284. thread_exit=1;
285. }else if(event.type==SFM_BREAK_EVENT){
286. break;
287. }
288. }
289. sws_freeContext(img_convert_ctx);
290. #if OUTPUT_YUV420P
291. fclose(fp_yuv);
292. #endif
293. SDL_Quit();
294. //av_free(out_buffer);
295. av_free(pFrameYUV);
296. avcodec_close(pCodecCtx);
297. avformat_close_input(&pFormatCtx);
298. return 0;
299. }

1. #define OUTPUT_YUV420P 0

1. //'1' Use Dshow
2. //'0' Use GDIgrab
3. #define USE_DSHOW 0

1. ::VS2010 Environment
2. call "D:\Program Files\Microsoft Visual Studio 10.0\VC\vcvarsall.bat"
3. ::include
4. @set INCLUDE=include;%INCLUDE%
5. ::lib
6. @set LIB=lib;%LIB%
7. ::compile and link
8. cl simplest_ffmpeg_grabdesktop.cpp /MD /link SDL.lib SDLmain.lib avcodec.lib ^
9. avformat.lib avutil.lib avdevice.lib avfilter.lib postproc.lib swresample.lib swscale.lib ^
10. /SUBSYSTEM:WINDOWS /OPT:NOREF

1. g++ simplest_ffmpeg_grabdesktop.cpp -g -o simplest_ffmpeg_grabdesktop.exe \
2. -I /usr/local/include -L /usr/local/lib \
3. -lmingw32 -lSDLmain -lSDL -lavformat -lavcodec -lavutil -lavdevice -lswscale

1. gcc simplest_ffmpeg_grabdesktop.cpp -g -o simplest_ffmpeg_grabdesktop.out \
2. -I /usr/local/include -L /usr/local/lib -lSDLmain -lSDL -lavformat -lavcodec -lavutil -lavdevice -lswscale

1. gcc simplest_ffmpeg_grabdesktop.cpp -g -o simplest_ffmpeg_grabdesktop.out \
2. -framework Cocoa -I /usr/local/include -L /usr/local/lib -lSDLmain -lSDL -lavformat -lavcodec -lavutil -lavdevice -lswscale