VS2013 / MFC + FFmpeg实现录屏

这是一个用FFmpeg实现的录屏功能，其中包括录制屏幕和声音，录制后的视屏为MPEG4 音频为AAC。主要程序就是创建了三个线程（ScreenCapThreadProc、AudioCapThreadProc、OutPutThreadProc）分别用来捕获桌面图片、捕获声音，将捕获到的桌面图片和声音写成一个视频文件。

ScreenCapThreadProc线程函数：

DWORD WINAPI ScreenCapThreadProc(LPVOID lpParam){AVPacket *packet = (AVPacket *)av_malloc(sizeof(AVPacket));int got_picture;AVFrame*pFrame;pFrame = av_frame_alloc();AVFrame *picture = av_frame_alloc();int size = avpicture_get_size(pFormatCtx_Out->streams[VideoIndex]->codec->pix_fmt,pFormatCtx_Out->streams[VideoIndex]->codec->width, pFormatCtx_Out->streams[VideoIndex]->codec->height);picture_buf = new uint8_t[size];avpicture_fill((AVPicture *)picture, picture_buf,pFormatCtx_Out->streams[VideoIndex]->codec->pix_fmt,pFormatCtx_Out->streams[VideoIndex]->codec->width,pFormatCtx_Out->streams[VideoIndex]->codec->height);FILE *p = NULL;p = fopen("proc_test.yuv", "wb+");int height = pFormatCtx_Out->streams[VideoIndex]->codec->height;int width = pFormatCtx_Out->streams[VideoIndex]->codec->width;int y_size = height*width;while (bCap){if (av_read_frame(pFormatCtx_Video, packet) < 0){continue;}if (packet->stream_index == 0){if (avcodec_decode_video2(pCodecCtx_Video, pFrame, &got_picture, packet) < 0){printf("Decode Error.（解码错误）\n");continue;}if (got_picture){sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0,pFormatCtx_Out->streams[VideoIndex]->codec->height, picture->data, picture->linesize);if (av_fifo_space(fifo_video) >= size){EnterCriticalSection(&VideoSection);av_fifo_generic_write(fifo_video, picture->data[0], y_size, NULL);av_fifo_generic_write(fifo_video, picture->data[1], y_size / 4, NULL);av_fifo_generic_write(fifo_video, picture->data[2], y_size / 4, NULL);LeaveCriticalSection(&VideoSection);}}}}av_frame_free(&pFrame);av_frame_free(&picture);delete[] picture_buf;return 0;}

AudioCapThreadProc线程函数：

DWORD WINAPI AudioCapThreadProc(LPVOID lpParam){AVPacket pkt;AVFrame *frame;frame = av_frame_alloc();int gotframe;while (bCap){if (av_read_frame(pFormatCtx_Audio, &pkt) < 0){continue;}if (avcodec_decode_audio4(pFormatCtx_Audio->streams[0]->codec, frame, &gotframe, &pkt) < 0){av_frame_free(&frame);printf("can not decoder a frame");break;}av_free_packet(&pkt);if (!gotframe){continue;//没有获取到数据，继续下一次}if (NULL == fifo_audio){fifo_audio = av_audio_fifo_alloc(pFormatCtx_Audio->streams[0]->codec->sample_fmt,pFormatCtx_Audio->streams[0]->codec->channels, 30 * frame->nb_samples);}int buf_space = av_audio_fifo_space(fifo_audio);if (av_audio_fifo_space(fifo_audio) >= frame->nb_samples){EnterCriticalSection(&AudioSection);av_audio_fifo_write(fifo_audio, (void **)frame->data, frame->nb_samples);LeaveCriticalSection(&AudioSection);}}av_frame_free(&frame);return 0;}

OutPutThreadProc线程函数：

DWORD WINAPI OutPutThreadProc(LPVOID lpParam){AVFrame *picture = av_frame_alloc();int size = avpicture_get_size(pFormatCtx_Out->streams[VideoIndex]->codec->pix_fmt,pFormatCtx_Out->streams[VideoIndex]->codec->width, pFormatCtx_Out->streams[VideoIndex]->codec->height);picture_buf = new uint8_t[size];avpicture_fill((AVPicture *)picture, picture_buf,pFormatCtx_Out->streams[VideoIndex]->codec->pix_fmt,pFormatCtx_Out->streams[VideoIndex]->codec->width,pFormatCtx_Out->streams[VideoIndex]->codec->height);int64_t cur_pts_v = 0, cur_pts_a = 0;int VideoFrameIndex = 0, AudioFrameIndex = 0;while (bCap){if (flagThread && bCap){bCap = false;Sleep(2000);//简单的用sleep等待采集线程关闭continue;}if (fifo_audio && fifo_video){int sizeAudio = av_audio_fifo_size(fifo_audio);int sizeVideo = av_fifo_size(fifo_video);//缓存数据写完就结束循环if (av_audio_fifo_size(fifo_audio) <= pFormatCtx_Out->streams[AudioIndex]->codec->frame_size &&av_fifo_size(fifo_video) <= frame_size && !bCap){break;}}if (av_compare_ts(cur_pts_v, pFormatCtx_Out->streams[VideoIndex]->time_base,cur_pts_a, pFormatCtx_Out->streams[AudioIndex]->time_base) <= 0){//read data from fifoif (av_fifo_size(fifo_video) < frame_size && !bCap){cur_pts_v = 0x7fffffffffffffff;}if (av_fifo_size(fifo_video) >= size){EnterCriticalSection(&VideoSection);av_fifo_generic_read(fifo_video, picture_buf, size, NULL);LeaveCriticalSection(&VideoSection);avpicture_fill((AVPicture *)picture, picture_buf,pFormatCtx_Out->streams[VideoIndex]->codec->pix_fmt,pFormatCtx_Out->streams[VideoIndex]->codec->width,pFormatCtx_Out->streams[VideoIndex]->codec->height);//pts = n * (（1 / timbase）/ fps);picture->pts = VideoFrameIndex * ((pFormatCtx_Video->streams[0]->time_base.den / pFormatCtx_Video->streams[0]->time_base.num) / 15);int got_picture = 0;AVPacket pkt;av_init_packet(&pkt);pkt.data = NULL;pkt.size = 0;int ret = avcodec_encode_video2(pFormatCtx_Out->streams[VideoIndex]->codec, &pkt, picture, &got_picture);if (ret < 0){//编码错误,不理会此帧continue;}if (got_picture == 1){pkt.stream_index = VideoIndex;pkt.pts = av_rescale_q_rnd(pkt.pts, pFormatCtx_Video->streams[0]->time_base,pFormatCtx_Out->streams[VideoIndex]->time_base, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));pkt.dts = av_rescale_q_rnd(pkt.dts, pFormatCtx_Video->streams[0]->time_base,pFormatCtx_Out->streams[VideoIndex]->time_base, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));pkt.duration = ((pFormatCtx_Out->streams[0]->time_base.den / pFormatCtx_Out->streams[0]->time_base.num) / 15);cur_pts_v = pkt.pts;ret = av_interleaved_write_frame(pFormatCtx_Out, &pkt);//delete[] pkt.data;av_free_packet(&pkt);}VideoFrameIndex++;}}else{if (NULL == fifo_audio){continue;//还未初始化fifo}if (av_audio_fifo_size(fifo_audio) < pFormatCtx_Out->streams[AudioIndex]->codec->frame_size && !bCap){cur_pts_a = 0x7fffffffffffffff;}if (av_audio_fifo_size(fifo_audio) >=(pFormatCtx_Out->streams[AudioIndex]->codec->frame_size > 0 ? pFormatCtx_Out->streams[AudioIndex]->codec->frame_size : 1024)){AVFrame *frame;frame = av_frame_alloc();frame->nb_samples = pFormatCtx_Out->streams[AudioIndex]->codec->frame_size > 0 ? pFormatCtx_Out->streams[AudioIndex]->codec->frame_size : 1024;frame->channel_layout = pFormatCtx_Out->streams[AudioIndex]->codec->channel_layout;frame->format = pFormatCtx_Out->streams[AudioIndex]->codec->sample_fmt;frame->sample_rate = pFormatCtx_Out->streams[AudioIndex]->codec->sample_rate;av_frame_get_buffer(frame, 0);EnterCriticalSection(&AudioSection);av_audio_fifo_read(fifo_audio, (void **)frame->data,(pFormatCtx_Out->streams[AudioIndex]->codec->frame_size > 0 ? pFormatCtx_Out->streams[AudioIndex]->codec->frame_size : 1024));LeaveCriticalSection(&AudioSection);if (pFormatCtx_Out->streams[0]->codec->sample_fmt != pFormatCtx_Audio->streams[AudioIndex]->codec->sample_fmt|| pFormatCtx_Out->streams[0]->codec->channels != pFormatCtx_Audio->streams[AudioIndex]->codec->channels|| pFormatCtx_Out->streams[0]->codec->sample_rate != pFormatCtx_Audio->streams[AudioIndex]->codec->sample_rate){//如果输入和输出的音频格式不一样 需要重采样，这里是一样的就没做}AVPacket pkt_out;av_init_packet(&pkt_out);int got_picture = -1;pkt_out.data = NULL;pkt_out.size = 0;frame->pts = AudioFrameIndex * pFormatCtx_Out->streams[AudioIndex]->codec->frame_size;if (avcodec_encode_audio2(pFormatCtx_Out->streams[AudioIndex]->codec, &pkt_out, frame, &got_picture) < 0){printf("can not decoder a frame");}av_frame_free(&frame);if (got_picture){pkt_out.stream_index = AudioIndex;pkt_out.pts = AudioFrameIndex * pFormatCtx_Out->streams[AudioIndex]->codec->frame_size;pkt_out.dts = AudioFrameIndex * pFormatCtx_Out->streams[AudioIndex]->codec->frame_size;pkt_out.duration = pFormatCtx_Out->streams[AudioIndex]->codec->frame_size;cur_pts_a = pkt_out.pts;int ret = av_interleaved_write_frame(pFormatCtx_Out, &pkt_out);av_free_packet(&pkt_out);}AudioFrameIndex++;}}}av_write_trailer(pFormatCtx_Out);avio_close(pFormatCtx_Out->pb);avformat_free_context(pFormatCtx_Out);if (pFormatCtx_Video != NULL){avformat_close_input(&pFormatCtx_Video);pFormatCtx_Video = NULL;}if (pFormatCtx_Audio != NULL){avformat_close_input(&pFormatCtx_Audio);pFormatCtx_Audio = NULL;}return 0;}

最后结果：

运行工程需要注意：在AudioCapThreadProc线程函数中以Direct Show的方式打开设备捕获声音时，需要使用ffmpeg命令显示本机的设备名称

ffmpeg命令：

ffmpeg -list_devices true -f dshow -i dummy

音频设备出现乱码，

解决办法1：把乱码ANSI转UTF-8

解决办法2：还有一种更简单的方式查看设备的名称。即不使用FFmpeg查看系统DirectShow输入设备的名称，而使用DirectShow SDK自带的工具GraphEdit（或者网上下一个GraphStudioNext）查看输入名称。

打开graphstudionext.exe，“图像->插入滤镜”

选择Audio Capture Sources来查看音频输入设备的简体中文名称

csdn源码下载：http://download.csdn.net/detail/davebobo/9492724