（高分求代码）基于ffmpeg 获取视频帧保存成图像转成yuv图像序列

#include <stdio.h>

#include <windows.h>

#include "string.h"

#include "stdlib.h"

// #include "avcodec.h"

// #include "avformat.h"

// #include "avutil.h"

// #include "flvdec.h"

#include "libavcodec/avcodec.h"

#include "libavformat/avformat.h"

#include "libavutil/avutil.h"

#include "libswscale/swscale.h"

#pragma comment(lib,"avcodec.lib")

#pragma comment(lib,"avformat.lib")

#pragma comment(lib,"avutil.lib")

#pragma comment(lib,"swscale.lib")

bool GetNextFrame(AVFormatContext *pFormatCtx, AVCodecContext *pCodecCtx, int videoStream, AVFrame *pFrame)

{

static AVPacket packet

static int bytesRemaining=0

static uint8_t *rawData

static bool fFirstTime=true

int bytesDecoded

int frameFinished

int ii = 0

AVPacket packettest

// First time we're called, set packet.data to NULL to indicate it

// doesn't have to be freed

if(fFirstTime)

{

fFirstTime=false

packet.data=NULL

}

// Decode packets until we have decoded a complete frame

while(true)

{

// Work on the current packet until we have decoded all of it

while(bytesRemaining >0)

{

// Decode the next chunk of data

bytesDecoded=avcodec_decode_video2(pCodecCtx, pFrame,

&frameFinished, &packet)//, rawData, bytesRemaining)

// Was there an error?

if(bytesDecoded <0)

{

fprintf(stderr, "Error while decoding frame\n")

return false

}

bytesRemaining-=bytesDecoded

rawData+=bytesDecoded

// Did we finish the current frame? Then we can return

if(frameFinished)

return true

}

// Read the next packet, skipping all packets that aren't for this

// stream

do

{

++ii

// Free old packet

if(packet.data!=NULL)

av_free_packet(&packet)

// Read new packet

if(/*av_read_packet*/av_read_frame(pFormatCtx, &packet)<0)

goto loop_exit

memcpy(&packettest, &packet, sizeof(AVPacket))

printf("%d\n", packet.stream_index)

} while(packet.stream_index!=videoStream)

bytesRemaining=packet.size

rawData=packet.data

}

loop_exit:

// Decode the rest of the last frame

bytesDecoded=avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished,

&packet)//, rawData, bytesRemaining)

// Free last packet

if(packet.data!=NULL)

av_free_packet(&packet)

return frameFinished!=0

}

void SaveFrame(AVFrame *pFrame, int width, int height, int iFrame)

{

FILE *pFile

char szFilename[32]

int y

/////////////////////

BITMAPFILEHEADER m_fileHeader

BITMAPINFOHEADER m_infoHeader

unsigned int uiTmp, uiTmp2

unsigned char *ucTmp = NULL

unsigned char ucRGB

int i

uiTmp = (width*3+3)/4*4*height

uiTmp2 = width*height*3

//文件标识"BM"（即0x4D42）表示位图

m_fileHeader.bfType = 0x4D42

//整个文件的大小（单位：字节）

m_fileHeader.bfSize = sizeof(m_fileHeader) + sizeof(m_infoHeader) + uiTmp

//保留。设置为0

m_fileHeader.bfReserved1 = 0

//保留。设置为0

m_fileHeader.bfReserved2 = 0

//从文件开始到位图数据的偏移量（单位：字节）

m_fileHeader.bfOffBits = sizeof(m_fileHeader) + sizeof(m_infoHeader)

//信息头长度（单位：字节）。典型值为28

m_infoHeader.biSize = 0x28

//位图宽度（单位：像素）

m_infoHeader.biWidth = width

//位图高度（单位：像素）。若其为正，表示倒向的位图。若为负，表示正向的位图

m_infoHeader.biHeight = height

//位图的面数（为1）

m_infoHeader.biPlanes = 1

//每个像素的位数

m_infoHeader.biBitCount = 24

//压缩说明。0(BI_RGB)表示不压缩

m_infoHeader.biCompression = 0

//用字节数表示的位图数据的大小（为4的位数）

m_infoHeader.biSizeImage = uiTmp

//水平分辨率（单位：像素/米）

m_infoHeader.biXPelsPerMeter = 0

//垂直分辨率（单位：像素/米）

m_infoHeader.biYPelsPerMeter = 0

//位图使用的颜色数

m_infoHeader.biClrUsed = 0

//重要的颜色数

m_infoHeader.biClrImportant = 0

/////////////////////

// Open file

sprintf(szFilename, "frame%d.bmp", iFrame)

pFile=fopen(szFilename, "wb")

if(pFile==NULL)

return

// Write header

// fprintf(pFile, "P6\n%d %d\n255\n", width, height)

// Write pixel data

fwrite(&m_fileHeader, sizeof(m_fileHeader), 1, pFile)

fwrite(&m_infoHeader, sizeof(m_infoHeader), 1, pFile)

for(y=height-1y>=0y--) {

if(ucTmp != NULL) {

delete []ucTmp

ucTmp = NULL

}

ucTmp = new unsigned char[width*3]

memcpy(ucTmp, pFrame->data[0]+y*pFrame->linesize[0], width*3)

for(i = 0i <widthi++) {

ucRGB = ucTmp[3*i]

ucTmp[3*i] = ucTmp[3*i+2]

ucTmp[3*i+2] = ucRGB

}

ucRGB = 0

fwrite(ucTmp, 1, width*3, pFile)

fwrite(&ucRGB, 1, (uiTmp-uiTmp2)/height , pFile)

}

// Close file

fclose(pFile)

}

int main(/*int argc, char *argv[]*/)

{

AVFormatContext *pFormatCtx

unsigned int i

int videoStream

AVCodecContext *pCodecCtx

AVCodec *pCodec

AVFrame *pFrame

AVFrame *pFrameRGB

int numBytes

uint8_t *buffer

AVInputFormat *fmt

char filename[50]

//printf("please input a filename:\n")

// scanf("%s",filename)

strcpy(filename,"chicken.avi")

// Register all formats and codecs

av_register_all()

//avformat_network_init()

//pFormatCtx=av_alloc_format_context()

// fmt = av_find_input_format("flv")

// pFormatCtx->iformat = fmt

// Open video file

if(av_open_input_file(&pFormatCtx,filename, /*fmt*/NULL, 0, NULL)!=0)

return -1// Couldn't open file

// Retrieve stream information

if(av_find_stream_info(pFormatCtx)<0)

return -1// Couldn't find stream information

// Dump information about file onto standard error

dump_format(pFormatCtx, 0, filename, false)

// Find the first video stream

videoStream=-1

for(i=0i<pFormatCtx->nb_streamsi++)

if(pFormatCtx->streams[i]->codec->codec_type==CODEC_TYPE_VIDEO)

{

videoStream=i

break

}

if(videoStream==-1)

return -1// Didn't find a video stream

// Get a pointer to the codec context for the video stream

pCodecCtx=pFormatCtx->streams[videoStream]->codec

// Find the decoder for the video stream

pCodec=avcodec_find_decoder(pCodecCtx->codec_id)

if(pCodec==NULL)

return -1// Codec not found

// Inform the codec that we can handle truncated bitstreams -- i.e.,

// bitstreams where frame boundaries can fall in the middle of packets

/*

if(pCodec->capabilities &CODEC_CAP_TRUNCATED)

pCodecCtx->flags|=CODEC_FLAG_TRUNCATED*/

// Open codec

if(avcodec_open(pCodecCtx, pCodec)<0)

return -1// Could not open codec

// Hack to correct wrong frame rates that seem to be generated by some

// codecs

/*

if(pCodecCtx->frame_rate>1000 &&pCodecCtx->frame_rate_base==1)

pCodecCtx->frame_rate_base=1000*/

// Allocate video frame

pFrame=avcodec_alloc_frame()

// Allocate an AVFrame structure

pFrameRGB=avcodec_alloc_frame()

if(pFrameRGB==NULL)

return -1

// Determine required buffer size and allocate buffer

numBytes=avpicture_get_size(PIX_FMT_RGB24/*PIX_FMT_YUV420P*/, pCodecCtx->width,

pCodecCtx->height)

buffer=(uint8_t*)av_malloc(numBytes*sizeof(uint8_t))

// Assign appropriate parts of buffer to image planes in pFrameRGB

avpicture_fill((AVPicture *)pFrameRGB, buffer, PIX_FMT_RGB24,

pCodecCtx->width, pCodecCtx->height)

// Read frames and save first five frames to disk

i=0

while(GetNextFrame(pFormatCtx, pCodecCtx, videoStream, pFrame))

{

// img_convert((AVPicture *)pFrameRGB, PIX_FMT_RGB24, (AVPicture*)pFrame,

// pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height)

// other codes

static struct SwsContext *img_convert_ctx

// other codes

img_convert_ctx = sws_getContext(pCodecCtx->width,

pCodecCtx->height,

pCodecCtx->pix_fmt,

pCodecCtx->width,

pCodecCtx->height,

PIX_FMT_RGB24,

SWS_BICUBIC, NULL,

NULL,

NULL)

// other codes

// Convert the image from its native format to RGB

sws_scale(img_convert_ctx,

(const uint8_t* const*)pFrame->data,

pFrame->linesize,

0,

pCodecCtx->height,

pFrameRGB->data,

pFrameRGB->linesize)

// Save the frame to disk

if(++i<=512)

SaveFrame(pFrameRGB, pCodecCtx->width, pCodecCtx->height, i)

}

printf("\n%d",i)

// Free the RGB image

// delete [] buffer

av_free(buffer)

av_free(pFrameRGB)

// Free the YUV frame

av_free(pFrame)

// Close the codec

avcodec_close(pCodecCtx)

// Close the video file

av_close_input_file(pFormatCtx)

return 0

}

这是网上找的代码，自己修改了一下，可以读取视频，并把视频中的帧转成对应的bmp图片。解码后的视频本来就是yuv格式的，只需要写入到相应的文件就可以了。

这个程序还需要相应的dll，lib和头文件。不过，这样没有办法传给你。

公式如下：

Y = 0.299R + 0.587G + 0.114B

U = -0.147R - 0.289G + 0.436B

V = 0.615R - 0.515G - 0.100B

R = Y + 1.14V

G = Y - 0.39U - 0.58V

B = Y + 2.03U

实例程序如下：

clear,clc

I=imread('Lena.jpg')

figure,imshow(I),title('原始图像')

I=double(I)

R=I(:,:,1)

G=I(:,:,2)

B=I(:,:,3)

Y = 0.299*R + 0.587*G + 0.114*B

U = -0.147*R - 0.289*G + 0.436*B

V = 0.615*R - 0.515*G - 0.100*B

J=cat(3,Y,U,V)

figure,imshow(J,[]),title('RGB转化为YUV的图像')

R1 = Y + 1.14*V

G1 = Y - 0.39*U - 0.58*V

B1= Y + 2.03*U

I1=cat(3,R1,G1,B1)

figure,imshow(uint8(I1)),title('YUV转化为RGB的图像')

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