最簡單的YUV422轉jpg的例程
阿新 • • 發佈:2018-12-25
原始碼:
/** * 最簡單的基於FFmpeg的影象編碼器 * Simplest FFmpeg Picture Encoder * * 雷霄驊 Lei Xiaohua * [email protected] * 中國傳媒大學/數字電視技術 * Communication University of China / Digital TV Technology * http://blog.csdn.net/leixiaohua1020 * * 本程式實現了YUV420P畫素資料編碼為JPEG圖片。是最簡單的FFmpeg編碼方面的教程。 * 通過學習本例子可以瞭解FFmpeg的編碼流程。 */ #include <stdio.h> #define __STDC_CONSTANT_MACROS #ifdef _WIN32 //Windows extern "C" { #include "libavcodec/avcodec.h" #include "libavformat/avformat.h" }; #else //Linux... #ifdef __cplusplus extern "C" { #endif #include <libavcodec/avcodec.h> #include <libavformat/avformat.h> #ifdef __cplusplus }; #endif #endif #define IMG_WIDTH 640 #define IMG_HEIGHT 480 int main(int argc, char* argv[]) { AVFormatContext* pFormatCtx; AVOutputFormat* fmt; AVStream* video_st; AVCodecContext* pCodecCtx; AVCodec* pCodec; uint8_t* picture_buf; AVFrame* picture; AVPacket pkt; int y_size; int got_picture=0; int size; int ret=0; FILE *in_file = NULL; //YUV source int in_w=IMG_WIDTH,in_h=IMG_HEIGHT; //YUV's width and height const char* out_file = "yuv422.jpg"; //Output file in_file = fopen("/home/jon/yuv422.yuv", "rb"); av_register_all(); //Method 1 pFormatCtx = avformat_alloc_context(); //Guess format fmt = av_guess_format("mjpeg", NULL, NULL); pFormatCtx->oformat = fmt; //Output URL if (avio_open(&pFormatCtx->pb,out_file, AVIO_FLAG_READ_WRITE) < 0){ printf("Couldn't open output file."); return -1; } //Method 2. More simple //avformat_alloc_output_context2(&pFormatCtx, NULL, NULL, out_file); //fmt = pFormatCtx->oformat; video_st = avformat_new_stream(pFormatCtx, 0); if (video_st==NULL){ return -1; } pCodecCtx = video_st->codec; pCodecCtx->codec_id = fmt->video_codec; pCodecCtx->codec_type = AVMEDIA_TYPE_VIDEO; pCodecCtx->pix_fmt = AV_PIX_FMT_YUVJ422P; pCodecCtx->width = in_w; pCodecCtx->height = in_h; pCodecCtx->time_base.num = 1; pCodecCtx->time_base.den = 25; //Output some information av_dump_format(pFormatCtx, 0, out_file, 1); pCodec = avcodec_find_encoder(pCodecCtx->codec_id); if (!pCodec){ printf("Codec not found."); return -1; } if (avcodec_open2(pCodecCtx, pCodec,NULL) < 0){ printf("Could not open codec."); return -1; } picture = av_frame_alloc(); size = avpicture_get_size(pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height); picture_buf = (uint8_t *)av_malloc(size); if (!picture_buf) { return -1; } avpicture_fill((AVPicture *)picture, picture_buf, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height); //Write Header avformat_write_header(pFormatCtx,NULL); y_size = pCodecCtx->width * pCodecCtx->height; av_new_packet(&pkt,y_size*3); //Read YUV if (fread(picture_buf, 1, y_size*2, in_file) <=0) { printf("Could not read input file."); return -1; } picture->data[0] = picture_buf; // Y picture->data[1] = picture_buf+ y_size; // U picture->data[2] = picture_buf+ y_size*3/2; // V //Encode ret = avcodec_encode_video2(pCodecCtx, &pkt,picture, &got_picture); if(ret < 0){ printf("Encode Error.\n"); return -1; } if (got_picture==1){ pkt.stream_index = video_st->index; ret = av_write_frame(pFormatCtx, &pkt); } av_free_packet(&pkt); //Write Trailer av_write_trailer(pFormatCtx); printf("Encode Successful.\n"); if (video_st){ avcodec_close(video_st->codec); av_free(picture); av_free(picture_buf); } avio_close(pFormatCtx->pb); avformat_free_context(pFormatCtx); fclose(in_file); return 0; }
生成的圖片(yuv422.jpg):