利用FFmpeg将视频文件生成bmp图像帧

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <windows.h>
#include "avformat.h"
#include "avcodec.h"
#include "swscale.h"

#pragma comment (lib, "avcodec.lib")
#pragma comment (lib, "avformat.lib")
#pragma comment (lib, "avutil.lib")
#pragma comment (lib, "swscale.lib")

#ifndef _WINGDI_
#define _WINGDI_
typedef struct tagBITMAPFILEHEADER {
WORD    bfType;
DWORD   bfSize;
WORD    bfReserved1;
WORD    bfReserved2;
DWORD   bfOffBits;
} BITMAPFILEHEADER, FAR *LPBITMAPFILEHEADER, *PBITMAPFILEHEADER;
typedef struct tagBITMAPINFOHEADER{
DWORD      biSize;
LONG       biWidth;
LONG       biHeight;
WORD       biPlanes;
WORD       biBitCount;
DWORD      biCompression;
DWORD      biSizeImage;
LONG       biXPelsPerMeter;
LONG       biYPelsPerMeter;
DWORD      biClrUsed;
DWORD      biClrImportant;
} BITMAPINFOHEADER, FAR *LPBITMAPINFOHEADER, *PBITMAPINFOHEADER;
#endif

void SaveAsBMP (AVFrame *pFrameRGB, int width, int height, int index, int bpp)
{
char buf[5] = {0};
BITMAPFILEHEADER bmpheader;
BITMAPINFOHEADER bmpinfo;
FILE *fp;
char filename[20] = "R:\\test";
_itoa (index, buf, 10);
strcat (filename, buf);
strcat (filename, ".bmp");

if ( (fp=fopen(filename,"wb+")) == NULL )
{
printf ("open file failed!\n");
return;
}
bmpheader.bfType = 0x4d42;
bmpheader.bfReserved1 = 0;
bmpheader.bfReserved2 = 0;
bmpheader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
bmpheader.bfSize = bmpheader.bfOffBits + width*height*bpp/8;
bmpinfo.biSize = sizeof(BITMAPINFOHEADER);
bmpinfo.biWidth = width;
bmpinfo.biHeight = height;
bmpinfo.biPlanes = 1;
bmpinfo.biBitCount = bpp;
bmpinfo.biCompression = BI_RGB;
bmpinfo.biSizeImage = (width*bpp+31)/32*4*height;
bmpinfo.biXPelsPerMeter = 100;
bmpinfo.biYPelsPerMeter = 100;
bmpinfo.biClrUsed = 0;
bmpinfo.biClrImportant = 0;
fwrite (&bmpheader, sizeof(bmpheader), 1, fp);
fwrite (&bmpinfo, sizeof(bmpinfo), 1, fp);
fwrite (pFrameRGB->data[0], width*height*bpp/8, 1, fp);
fclose(fp);
}

int main (void)
{
unsigned int i = 0, videoStream = -1;
AVCodecContext *pCodecCtx;
AVFormatContext *pFormatCtx;
AVCodec *pCodec;
AVFrame *pFrame, *pFrameRGB;
struct SwsContext *pSwsCtx;
const char *filename = "test.avi";
AVPacket packet;
int frameFinished;
int PictureSize;
uint8_t *buf;
av_register_all();
if ( av_open_input_file(&pFormatCtx, filename, NULL, 0, NULL) != 0 )
{
printf ("av open input file failed!\n");
exit (1);
}
if ( av_find_stream_info(pFormatCtx) < 0 )
{
printf ("av find stream info failed!\n");
exit (1);
}
for ( i=0; i<pFormatCtx->nb_streams; i++ )
if ( pFormatCtx->streams[i]->codec->codec_type == CODEC_TYPE_VIDEO )
{
videoStream = i;
break;
}
if (videoStream == -1)
{
printf ("find video stream failed!\n");
exit (1);
}
pCodecCtx = pFormatCtx->streams[videoStream]->codec;
pCodec = avcodec_find_decoder (pCodecCtx->codec_id);
if (pCodec == NULL)
{
printf ("avcode find decoder failed!\n");
exit (1);
}

if ( avcodec_open(pCodecCtx, pCodec)<0 )
{
printf ("avcode open failed!\n");
exit (1);
}

pFrame = avcodec_alloc_frame();
pFrameRGB = avcodec_alloc_frame();

if ( (pFrame==NULL)||(pFrameRGB==NULL) )
{
printf("avcodec alloc frame failed!\n");
exit (1);
}
PictureSize = avpicture_get_size (PIX_FMT_BGR24, pCodecCtx->width, pCodecCtx->height);
buf = av_malloc(PictureSize);
if ( buf == NULL )
{
printf( "av malloc failed!\n");
exit(1);
}
avpicture_fill ( (AVPicture *)pFrameRGB, buf, PIX_FMT_BGR24, pCodecCtx->width, pCodecCtx->height);
pSwsCtx = sws_getContext (pCodecCtx->width,
pCodecCtx->height,
pCodecCtx->pix_fmt,
pCodecCtx->width,
pCodecCtx->height,
PIX_FMT_BGR24,
SWS_BICUBIC,
NULL, NULL, NULL);
i = 0;
while(av_read_frame(pFormatCtx, &packet) >= 0)
{
if(packet.stream_index==videoStream)
{
avcodec_decode_video(pCodecCtx, pFrame, &frameFinished, packet.data, packet.size);

if(frameFinished)
{
//反转图像
//*(pFrame->data[0]) =  pCodecCtx->width * (pCodecCtx->height-1);
//pFrame ->linesize[0] = -(pCodecCtx->height);
pFrame->data[0] += pFrame->linesize[0] * (pCodecCtx->height - 1);
pFrame->linesize[0] *= -1;
pFrame->data[1] += pFrame->linesize[1] * (pCodecCtx->height / 2 - 1);
pFrame->linesize[1] *= -1;
pFrame->data[2] += pFrame->linesize[2] * (pCodecCtx->height / 2 - 1);
pFrame->linesize[2] *= -1;

sws_scale (pSwsCtx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);
SaveAsBMP (pFrameRGB, pCodecCtx->width, pCodecCtx->height, i++, 24);
}
}
av_free_packet(&packet);
}
sws_freeContext (pSwsCtx);
av_free (pFrame);
av_free (pFrameRGB);
avcodec_close (pCodecCtx);
av_close_input_file (pFormatCtx);
return 0;
}