ffmpeg实现YUV420缩放

读取YUV文件，然后实现将YUV视频缩小，直接上code：

#include <stdio.h>#include <unistd.h>#include <libswscale/swscale.h>#include <libavutil/frame.h>#include <libavcodec/avcodec.h>typedef struct{  unsigned int height;  unsigned int width;  unsigned long bufferSize;  unsigned char *bufferPtr;  }ImgInfo;int scale_one_img(ImgInfo *rawData, ImgInfo *resizedYuvData, uint8_t * m_pVideoOutput_ZoomBuf, int m_pVideoOutput_Zoomsize){int nSrcH = rawData->height;int nSrcW = rawData->width;int nDstH = resizedYuvData->height;int nDstW = resizedYuvData->width;AVFrame *p_input_frame = av_frame_alloc();AVFrame *p_output_frame = av_frame_alloc();avpicture_fill((AVPicture *)p_output_frame, (unsigned char *)m_pVideoOutput_ZoomBuf, AV_PIX_FMT_YUV420P, nDstW, nDstH);struct SwsContext* m_pSwsContext;m_pSwsContext = sws_getContext(nSrcW, nSrcH, AV_PIX_FMT_YUV420P, nDstW, nDstH, AV_PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);  if (NULL == m_pSwsContext)   {  printf("ffmpeg get context error!\n");  return -1;  }avpicture_fill((AVPicture *)p_input_frame, rawData->bufferPtr, AV_PIX_FMT_YUV420P, nSrcW, nSrcH);sws_scale(m_pSwsContext, p_input_frame->data, p_input_frame->linesize, 0, nSrcH, p_output_frame->data, p_output_frame->linesize);  memcpy(resizedYuvData->bufferPtr, m_pVideoOutput_ZoomBuf, m_pVideoOutput_Zoomsize);sws_freeContext(m_pSwsContext);return m_pVideoOutput_Zoomsize;}FILE *init_file(char *file_name, char *mod){FILE *fp = fopen(file_name, mod);if(fp == NULL){printf("error when open file %s\n", file_name);exit(1);}return fp;}void close_file(FILE *fp){fclose(fp);}ImgInfo *img_init(int w, int h){ImgInfo *img = (ImgInfo *)malloc(sizeof(ImgInfo));img->height = h;img->width = w;img->bufferSize = w * h * 3 / 2;img->bufferPtr = (unsigned char *)malloc(img->bufferSize * 2);if(img->bufferPtr == NULL){printf("error when malloc for bufferPtr\n");exit(1);}return img;}void img_release(ImgInfo *img){free(img->bufferPtr);free(img);}int deal_one_file(){int nSrcW = 1280, nSrcH = 720;FILE *fp_input = init_file("input.yuv", "rb");ImgInfo *src_img = img_init(nSrcW, nSrcH);int nDstW = 320, nDstH = 240;FILE *fp_output = init_file("output.yuv", "wb");ImgInfo *dst_img = img_init(nDstW, nDstH);int num = 0;int ret;uint8_t * m_pVideoOutput_ZoomBuf = NULL;  int m_pVideoOutput_Zoomsize = 0;m_pVideoOutput_Zoomsize = avpicture_get_size(AV_PIX_FMT_YUV420P, nDstW, nDstH);  m_pVideoOutput_ZoomBuf =( uint8_t *)calloc(1, m_pVideoOutput_Zoomsize * 3 * sizeof(char)); //最大分配的空间，能满足yuv的各种格式  while(!feof(fp_input)){ret = fread(src_img->bufferPtr, 1, src_img->bufferSize, fp_input);if(ret < src_img->bufferSize){printf("read data over\n");break;}printf("read one frame num = %d\n", num++);ret = scale_one_img(src_img, dst_img, m_pVideoOutput_ZoomBuf, m_pVideoOutput_Zoomsize);fwrite(dst_img->bufferPtr, 1, ret, fp_output);if(num > 500){break;}}free(m_pVideoOutput_ZoomBuf);fclose(fp_input);fclose(fp_output);img_release(src_img);img_release(dst_img);return 1;}int main(){deal_one_file();return 1;}