FFmpeg代码实现视频转jpg图片(解决运行过程中内存增长问题)
1、参考FFmpeg版本：ffmpeg-4.0
2、源码
//头文件
#include <libavutil/timestamp.h>
#include <libavformat/avformat.h>int saveJpg(AVFrame *pFrame, char *out_name);int main(int argc, char *argv[]) {int ret;const char *in_filename, *out_filename;AVFormatContext *fmt_ctx = NULL;const AVCodec *codec;AVCodecContext *codeCtx = NULL;AVStream *stream = NULL;int stream_index;AVPacket avpkt;int frame_count;AVFrame *frame;// if (argc <= 2) {
// printf("Usage: %s <input file> <output file>\n", argv[0]);
// exit(0);
// }
// in_filename = argv[1];
// out_filename = argv[2];in_filename = "rtsp://192.168.2.22:554/live1.sdp";out_filename = "Snapshot";//测试时先创建好该文件夹// 1if (avformat_open_input(&fmt_ctx, in_filename, NULL, NULL) < 0) {printf("Could not open source file %s\n", in_filename);exit(1);}if (avformat_find_stream_info(fmt_ctx, NULL) < 0) {printf("Could not find stream information\n");exit(1);}av_dump_format(fmt_ctx, 0, in_filename, 0);av_init_packet(&avpkt);avpkt.data = NULL;avpkt.size = 0;// 2stream_index = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, 0);if (ret < 0) {fprintf(stderr, "Could not find %s stream in input file '%s'\n",av_get_media_type_string(AVMEDIA_TYPE_VIDEO), in_filename);return ret;}stream = fmt_ctx->streams[stream_index];// 3codec = avcodec_find_decoder(stream->codecpar->codec_id);if (codec == NULL) {return -1;}// 4codeCtx = avcodec_alloc_context3(NULL);if (!codeCtx) {fprintf(stderr, "Could not allocate video codec context\n");exit(1);}// 5if ((ret = avcodec_parameters_to_context(codeCtx, stream->codecpar)) < 0) {fprintf(stderr, "Failed to copy %s codec parameters to decoder context\n",av_get_media_type_string(AVMEDIA_TYPE_VIDEO));return ret;}// 6avcodec_open2(codeCtx, codec, NULL);//初始化frame，解码后数据frame = av_frame_alloc();if (!frame) {fprintf(stderr, "Could not allocate video frame\n");exit(1);}frame_count = 0;char buf[1024];// 7while (av_read_frame(fmt_ctx, &avpkt) >= 0) {if (avpkt.stream_index == stream_index) {// 8int re = avcodec_send_packet(codeCtx, &avpkt);if (re < 0) {//增加av_packet_unref(&avpkt);av_packet_unref(&avpkt);continue;}// 9 这里必须用while()，因为一次avcodec_receive_frame可能无法接收到所有数据while (avcodec_receive_frame(codeCtx, frame) == 0) {// 拼接图片路径、名称snprintf(buf, sizeof(buf), "%s/Demo-%d.jpg", out_filename, frame_count);if ( !saveJpg(frame, buf) ){//保存为jpg图片remove(buf);printf("Removed file:%s\n",buf);//break;}}frame_count++;if( frame_count >=100 )frame_count = 0;}av_packet_unref(&avpkt);}
}int saveJpg(AVFrame *pFrame, char *out_name) {int width = pFrame->width;int height = pFrame->height;AVCodecContext *pCodeCtx = NULL;AVFormatContext *pFormatCtx = avformat_alloc_context();// 设置输出文件格式pFormatCtx->oformat = av_guess_format("mjpeg", NULL, NULL);// 创建并初始化输出AVIOContextif (avio_open(&pFormatCtx->pb, out_name, AVIO_FLAG_READ_WRITE) < 0) {printf("Couldn't open output file.");return -1;}// 构建一个新streamAVStream *pAVStream = avformat_new_stream(pFormatCtx, 0);if (pAVStream == NULL) {return -1;}AVCodecParameters *parameters = pAVStream->codecpar;parameters->codec_id = pFormatCtx->oformat->video_codec;parameters->codec_type = AVMEDIA_TYPE_VIDEO;parameters->format = AV_PIX_FMT_YUVJ420P;parameters->width = pFrame->width;parameters->height = pFrame->height;AVCodec *pCodec = avcodec_find_encoder(pAVStream->codecpar->codec_id);if (!pCodec) {printf("Could not find encoder\n");return -1;}pCodeCtx = avcodec_alloc_context3(pCodec);if (!pCodeCtx) {fprintf(stderr, "Could not allocate video codec context\n");exit(1);}if ((avcodec_parameters_to_context(pCodeCtx, pAVStream->codecpar)) < 0) {fprintf(stderr, "Failed to copy %s codec parameters to decoder context\n",av_get_media_type_string(AVMEDIA_TYPE_VIDEO));return -1;}pCodeCtx->time_base = (AVRational) {1, 25};if (avcodec_open2(pCodeCtx, pCodec, NULL) < 0) {printf("Could not open codec.");return -1;}int ret = avformat_write_header(pFormatCtx, NULL);if (ret < 0) {printf("write_header fail\n");return -1;}int y_size = width * height;//Encode// 给AVPacket分配足够大的空间AVPacket pkt;av_new_packet(&pkt, y_size * 3);// 编码数据ret = avcodec_send_frame(pCodeCtx, pFrame);if (ret < 0) {printf("Could not avcodec_send_frame.");return -1;}// 得到编码后数据ret = avcodec_receive_packet(pCodeCtx, &pkt);if (ret < 0) {printf("Could not avcodec_receive_packet");return -1;}ret = av_write_frame(pFormatCtx, &pkt);if (ret < 0) {printf("Could not av_write_frame");return -1;}av_packet_unref(&pkt);//Write Trailerav_write_trailer(pFormatCtx);//avcodec_close(pCodeCtx);//替换成avcodec_free_context(&pCodeCtx);avcodec_free_context(&pCodeCtx);avio_close(pFormatCtx->pb);avformat_free_context(pFormatCtx);return 0;
}
3、参考博客
FFmpeg代码实现视频转jpg图片(解决运行过程中内存增长问题)
1、参考FFmpeg版本：ffmpeg-4.0
2、源码
//头文件
#include <libavutil/timestamp.h>
#include <libavformat/avformat.h>int saveJpg(AVFrame *pFrame, char *out_name);int main(int argc, char *argv[]) {int ret;const char *in_filename, *out_filename;AVFormatContext *fmt_ctx = NULL;const AVCodec *codec;AVCodecContext *codeCtx = NULL;AVStream *stream = NULL;int stream_index;AVPacket avpkt;int frame_count;AVFrame *frame;// if (argc <= 2) {
// printf("Usage: %s <input file> <output file>\n", argv[0]);
// exit(0);
// }
// in_filename = argv[1];
// out_filename = argv[2];in_filename = "rtsp://192.168.2.22:554/live1.sdp";out_filename = "Snapshot";//测试时先创建好该文件夹// 1if (avformat_open_input(&fmt_ctx, in_filename, NULL, NULL) < 0) {printf("Could not open source file %s\n", in_filename);exit(1);}if (avformat_find_stream_info(fmt_ctx, NULL) < 0) {printf("Could not find stream information\n");exit(1);}av_dump_format(fmt_ctx, 0, in_filename, 0);av_init_packet(&avpkt);avpkt.data = NULL;avpkt.size = 0;// 2stream_index = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, 0);if (ret < 0) {fprintf(stderr, "Could not find %s stream in input file '%s'\n",av_get_media_type_string(AVMEDIA_TYPE_VIDEO), in_filename);return ret;}stream = fmt_ctx->streams[stream_index];// 3codec = avcodec_find_decoder(stream->codecpar->codec_id);if (codec == NULL) {return -1;}// 4codeCtx = avcodec_alloc_context3(NULL);if (!codeCtx) {fprintf(stderr, "Could not allocate video codec context\n");exit(1);}// 5if ((ret = avcodec_parameters_to_context(codeCtx, stream->codecpar)) < 0) {fprintf(stderr, "Failed to copy %s codec parameters to decoder context\n",av_get_media_type_string(AVMEDIA_TYPE_VIDEO));return ret;}// 6avcodec_open2(codeCtx, codec, NULL);//初始化frame，解码后数据frame = av_frame_alloc();if (!frame) {fprintf(stderr, "Could not allocate video frame\n");exit(1);}frame_count = 0;char buf[1024];// 7while (av_read_frame(fmt_ctx, &avpkt) >= 0) {if (avpkt.stream_index == stream_index) {// 8int re = avcodec_send_packet(codeCtx, &avpkt);if (re < 0) {//增加av_packet_unref(&avpkt);av_packet_unref(&avpkt);continue;}// 9 这里必须用while()，因为一次avcodec_receive_frame可能无法接收到所有数据while (avcodec_receive_frame(codeCtx, frame) == 0) {// 拼接图片路径、名称snprintf(buf, sizeof(buf), "%s/Demo-%d.jpg", out_filename, frame_count);if ( !saveJpg(frame, buf) ){//保存为jpg图片remove(buf);printf("Removed file:%s\n",buf);//break;}}frame_count++;if( frame_count >=100 )frame_count = 0;}av_packet_unref(&avpkt);}
}int saveJpg(AVFrame *pFrame, char *out_name) {int width = pFrame->width;int height = pFrame->height;AVCodecContext *pCodeCtx = NULL;AVFormatContext *pFormatCtx = avformat_alloc_context();// 设置输出文件格式pFormatCtx->oformat = av_guess_format("mjpeg", NULL, NULL);// 创建并初始化输出AVIOContextif (avio_open(&pFormatCtx->pb, out_name, AVIO_FLAG_READ_WRITE) < 0) {printf("Couldn't open output file.");return -1;}// 构建一个新streamAVStream *pAVStream = avformat_new_stream(pFormatCtx, 0);if (pAVStream == NULL) {return -1;}AVCodecParameters *parameters = pAVStream->codecpar;parameters->codec_id = pFormatCtx->oformat->video_codec;parameters->codec_type = AVMEDIA_TYPE_VIDEO;parameters->format = AV_PIX_FMT_YUVJ420P;parameters->width = pFrame->width;parameters->height = pFrame->height;AVCodec *pCodec = avcodec_find_encoder(pAVStream->codecpar->codec_id);if (!pCodec) {printf("Could not find encoder\n");return -1;}pCodeCtx = avcodec_alloc_context3(pCodec);if (!pCodeCtx) {fprintf(stderr, "Could not allocate video codec context\n");exit(1);}if ((avcodec_parameters_to_context(pCodeCtx, pAVStream->codecpar)) < 0) {fprintf(stderr, "Failed to copy %s codec parameters to decoder context\n",av_get_media_type_string(AVMEDIA_TYPE_VIDEO));return -1;}pCodeCtx->time_base = (AVRational) {1, 25};if (avcodec_open2(pCodeCtx, pCodec, NULL) < 0) {printf("Could not open codec.");return -1;}int ret = avformat_write_header(pFormatCtx, NULL);if (ret < 0) {printf("write_header fail\n");return -1;}int y_size = width * height;//Encode// 给AVPacket分配足够大的空间AVPacket pkt;av_new_packet(&pkt, y_size * 3);// 编码数据ret = avcodec_send_frame(pCodeCtx, pFrame);if (ret < 0) {printf("Could not avcodec_send_frame.");return -1;}// 得到编码后数据ret = avcodec_receive_packet(pCodeCtx, &pkt);if (ret < 0) {printf("Could not avcodec_receive_packet");return -1;}ret = av_write_frame(pFormatCtx, &pkt);if (ret < 0) {printf("Could not av_write_frame");return -1;}av_packet_unref(&pkt);//Write Trailerav_write_trailer(pFormatCtx);//avcodec_close(pCodeCtx);//替换成avcodec_free_context(&pCodeCtx);avcodec_free_context(&pCodeCtx);avio_close(pFormatCtx->pb);avformat_free_context(pFormatCtx);return 0;
}
3、参考博客
发布评论