使用ffmpeg创建视频

我有100个图像（PNG），我想用这些图像创建一个视频。我使用的是ffmpeg库。使用命令行，我可以轻松创建视频。但是我该如何通过编码来实现呢？

任何帮助都将不胜感激。

#pragma GCC diagnostic ignored "-Wdeprecated-declarations"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#ifdef HAVE_AV_CONFIG_H
#undef HAVE_AV_CONFIG_H
#endif
extern "C"
{
#include "libavutil/imgutils.h"
#include "libavutil/opt.h"
#include "libavcodec/avcodec.h"
#include "libavutil/mathematics.h"
#include "libavutil/samplefmt.h"
}
#define INBUF_SIZE 4096
#define AUDIO_INBUF_SIZE 20480
#define AUDIO_REFILL_THRESH 4096


static void video_encode_example(const char *filename, int codec_id)
{
   AVCodec *codec;
   AVCodecContext *c= NULL;
   int i, out_size, size, x, y, outbuf_size;
   FILE *f;
   AVFrame *picture;
   uint8_t *outbuf;
   int nrOfFramesPerSecond  =25;
   int nrOfSeconds =1;

   printf("Video encodingn");
//    find the mpeg1 video encoder
   codec = avcodec_find_encoder((CodecID) codec_id);
   if (!codec) {
       fprintf(stderr, "codec not foundn");
       exit(1);
   }
   c = avcodec_alloc_context3(codec);
   picture= avcodec_alloc_frame();
//    put sample parameters
   c->bit_rate = 400000;
//    resolution must be a multiple of two
   c->width = 352;
   c->height = 288;
//    frames per second
   c->time_base= (AVRational){1,25};
   c->gop_size = 10;  //emit one intra frame every ten frames
   c->max_b_frames=1;
   c->pix_fmt = PIX_FMT_YUV420P;
   if(codec_id == CODEC_ID_H264)
       av_opt_set(c->priv_data, "preset", "slow", 0);
//    open it
   if (avcodec_open2(c, codec, NULL) < 0) {
       fprintf(stderr, "could not open codecn");
       exit(1);
   }
   f = fopen(filename, "wb");
   if (!f) {
       fprintf(stderr, "could not open %sn", filename);
       exit(1);
   }
//    alloc image and output buffer
   outbuf_size = 100000;
   outbuf = (uint8_t*) malloc(outbuf_size);
//    the image can be allocated by any means and av_image_alloc() is
//    * just the most convenient way if av_malloc() is to be used
   av_image_alloc(picture->data, picture->linesize,
                  c->width, c->height, c->pix_fmt, 1);
//    encode 1 second of video
   int nrOfFramesTotal = nrOfFramesPerSecond * nrOfSeconds;
//    encode 1 second of video
   for(i=0;i < nrOfFramesTotal; i++) {
       fflush(stdout);
//        prepare a dummy image
       for(y=0;y<c->height;y++) {
           for(x=0;x<c->width;x++) {
               picture->data[0][y * picture->linesize[0] + x] = x + y + i * 3;
           }
       }
//        Cb and Cr
       for(y=0;y<c->height/2;y++) {
           for(x=0;x<c->width/2;x++) {
               picture->data[1][y * picture->linesize[1] + x] = 128 + y + i * 2;
               picture->data[2][y * picture->linesize[2] + x] = 64 + x + i * 5;
           }
       }
//        encode the image
       out_size = avcodec_encode_video(c, outbuf, outbuf_size, picture);
       printf("encoding frame %3d (size=%5d)n", i, out_size);
       fwrite(outbuf, 1, out_size, f);
   }
//    get the delayed frames
   for(; out_size; i++) {
       fflush(stdout);
       out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL);
       printf("write frame %3d (size=%5d)n", i, out_size);
       fwrite(outbuf, 1, out_size, f);
   }
//    add sequence end code to have a real mpeg file
   outbuf[0] = 0x00;
   outbuf[1] = 0x00;
   outbuf[2] = 0x01;
   outbuf[3] = 0xb7;
   fwrite(outbuf, 1, 4, f);
   fclose(f);
   free(outbuf);
   avcodec_close(c);
//   av_free(c);
//   av_free(picture->data[0]);
//   av_free(picture);
   printf("n");
}
int main(int argc, char **argv)
{
   const char *filename;

   avcodec_register_all();
   if (argc <= 1) {
       video_encode_example("/home/radix/Desktop/OpenCV/FFMPEG_Output/op89.png", AV_CODEC_ID_H264);
   } else {
       filename = argv[1];
   }

   return 0;
}

• 每次搜索时我都会得到类似的代码。但我不理解hot用它来创建图像视频