前面本来说是做h264编码的 研究了两天发现ffmpeg里的h264编码似乎是要信赖第三方库x264 还是怎么简单怎么来吧所以就整了个mpeg编码 ffmpeg移植前面我有一篇ffmpeg解码里已经给了 具体链接在这http://blog.csdn.net/hclydao/article/details/18546757
怎么使用那里面也已经说了 这里主要是通过ffmpeg将yuv422格式转换成rgb 然后就是yuv422转成mpeg格式 接前面几篇 获取到yuv422数据后 为了能显示出来 所以先转换成rgb565的数据 接口函数如下
/* * yuv to rgb */ JNIEXPORT jint JNICALL Java_com_hclydao_webcam_Ffmpeg_yuvtorgb(JNIEnv * env, jclass obj,const jbyteArray yuvdata, jbyteArray rgbdata,const jint dwidth,const jint dheight) { jbyte *ydata = (jbyte*)(*env)->GetByteArrayElements(env, yuvdata, 0); jbyte *rdata = (jbyte*)(*env)->GetByteArrayElements(env, rgbdata, 0); AVFrame * rpicture=NULL; AVFrame * ypicture=NULL; struct SwsContext *swsctx = NULL; rpicture=avcodec_alloc_frame(); ypicture=avcodec_alloc_frame(); avpicture_fill((AVPicture *) rpicture, (uint8_t *)rdata, PIX_FMT_RGB565,dwidth,dheight); avpicture_fill((AVPicture *) ypicture, (uint8_t *)ydata, AV_PIX_FMT_YUYV422,mwidth,mheight); swsctx = sws_getContext(mwidth,mheight, AV_PIX_FMT_YUYV422, dwidth, dheight,PIX_FMT_RGB565, SWS_BICUBIC, NULL, NULL, NULL); sws_scale(swsctx,(const uint8_t* const*)ypicture->data,ypicture->linesize,0,mheight,rpicture->data,rpicture->linesize); sws_freeContext(swsctx); av_free(rpicture); av_free(ypicture); (*env)->ReleaseByteArrayElements(env, yuvdata, ydata, 0); (*env)->ReleaseByteArrayElements(env, rgbdata, rdata, 0); return 0; }
然后就是mpeg编码了 网上说ffmpeg只能将yuv420p的编码 所以要先将yuv422转成yuv420p后在进行编码 相关接口函数如下
AVCodecContext *pCodecCtx= NULL; AVPacket avpkt; FILE * video_file; unsigned char *outbuf=NULL; unsigned char *yuv420buf=NULL; static int outsize=0; /* * encording init */ JNIEXPORT jint JNICALL Java_com_hclydao_webcam_Ffmpeg_videoinit(JNIEnv * env, jclass obj,jbyteArray filename) { LOGI("%s\n",__func__); AVCodec * pCodec=NULL; avcodec_register_all(); pCodec=avcodec_find_encoder(AV_CODEC_ID_MPEG1VIDEO); if(pCodec == NULL) { LOGE("++++++++++++codec not found\n"); return -1; } pCodecCtx=avcodec_alloc_context3(pCodec); if (pCodecCtx == NULL) { LOGE("++++++Could not allocate video codec context\n"); return -1; } /* put sample parameters */ pCodecCtx->bit_rate = 400000; /* resolution must be a multiple of two */ pCodecCtx->width = mwidth; pCodecCtx->height = mheight; /* frames per second */ pCodecCtx->time_base= (AVRational){1,25}; pCodecCtx->gop_size = 10; /* emit one intra frame every ten frames */ pCodecCtx->max_b_frames=1; pCodecCtx->pix_fmt = AV_PIX_FMT_YUV420P;//AV_PIX_FMT_YUYV422; /* open it */ if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0) { LOGE("+++++++Could not open codec\n"); return -1; } outsize = mwidth * mheight*2; outbuf = malloc(outsize*sizeof(char)); yuv420buf = malloc(outsize*sizeof(char)); jbyte *filedir = (jbyte*)(*env)->GetByteArrayElements(env, filename, 0); if ((video_file = fopen(filedir, "wb")) == NULL) { LOGE("++++++++++++open %s failed\n",filedir); return -1; } (*env)->ReleaseByteArrayElements(env, filename, filedir, 0); return 1; } JNIEXPORT jint JNICALL Java_com_hclydao_webcam_Ffmpeg_videostart(JNIEnv * env, jclass obj,jbyteArray yuvdata) { int frameFinished=0,size=0; jbyte *ydata = (jbyte*)(*env)->GetByteArrayElements(env, yuvdata, 0); AVFrame * yuv420pframe=NULL; AVFrame * yuv422frame=NULL; struct SwsContext *swsctx = NULL; yuv420pframe=avcodec_alloc_frame(); yuv422frame=avcodec_alloc_frame(); avpicture_fill((AVPicture *) yuv420pframe, (uint8_t *)yuv420buf, AV_PIX_FMT_YUV420P,mwidth,mheight); avpicture_fill((AVPicture *) yuv422frame, (uint8_t *)ydata, AV_PIX_FMT_YUYV422,mwidth,mheight); swsctx = sws_getContext(mwidth,mheight, AV_PIX_FMT_YUYV422, mwidth, mheight,AV_PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL); sws_scale(swsctx,(const uint8_t* const*)yuv422frame->data,yuv422frame->linesize,0,mheight,yuv420pframe->data,yuv420pframe->linesize); av_init_packet(&avpkt); size = avcodec_encode_video2(pCodecCtx, &avpkt, yuv420pframe, &frameFinished); if (size < 0) { LOGE("+++++Error encoding frame\n"); return -1; } if(frameFinished) fwrite(avpkt.data,avpkt.size,1,video_file); av_free_packet(&avpkt); sws_freeContext(swsctx); av_free(yuv420pframe); av_free(yuv422frame); (*env)->ReleaseByteArrayElements(env, yuvdata, ydata, 0); } JNIEXPORT jint JNICALL Java_com_hclydao_webcam_Ffmpeg_videoclose(JNIEnv * env, jclass obj) { fclose(video_file); avcodec_close(pCodecCtx); av_free(pCodecCtx); free(outbuf); }最后录下来的视频是可以用播放的 总感觉代码好像哪里写的不对 bug总是有的 过程和原理搞清楚了其它就容易了
下面是我录的 至此摄像头这块暂时就这样了
这测试我又重新新建了一个工程
整个工程下载链接 请去我的资源里找吧 我上传了没显示出来 那个有20几M的就是的了
这个bug很多 没怎么认真去写 如果原理和过程有问题的希望大家指出