学步园

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http://yeyingxian.blog.163.com/blog/static/344712420096296270569/

yuv2avi，用ffmpeg SDK做的，用的还是output_example.c的一套代码。关键是写好codec_tag，I420是YUV格式，YV12是YVU格式。ffmpeg sdk下载地址
http://www.bairuitech.com/html/ruanjianxiazai/ffmpeg/20080414/89.html

#include "libavformat/avformat.h"

const int WIDTH = 320;
const int HEIGHT = 240;
unsigned char buf[WIDTH *HEIGHT *3];

int main()
{
    int i;

    FILE *fin = fopen("e:\\1031.yuv", "rb");
    AVOutputFormat *pOutputFormat;
    AVFormatContext *pFormatCtxEnc;
    AVStream *video_st;
    AVCodecContext *pCodecCtxEnc;
    const char *filename = "1.avi";

    av_register_all();
    // auto detect the output format from the name
    pOutputFormat = guess_format(NULL, filename, NULL);

    // allocate the output media context
    pFormatCtxEnc = av_alloc_format_context();
    pFormatCtxEnc->oformat = pOutputFormat;
    snprintf(pFormatCtxEnc->filename, sizeof(pFormatCtxEnc->filename), "%s", filename);

    video_st = av_new_stream(pFormatCtxEnc, 0);

    pCodecCtxEnc = video_st->codec;

    pCodecCtxEnc->codec_id = CODEC_ID_RAWVIDEO;
    pCodecCtxEnc->codec_type = CODEC_TYPE_VIDEO;
    pCodecCtxEnc->codec_tag = MKTAG('I', '4', '2', '0');

    // put sample parameters 
    // resolution must be a multiple of two 
    pCodecCtxEnc->width = WIDTH;
    pCodecCtxEnc->height = HEIGHT;
    // frames per second 
    pCodecCtxEnc->time_base.den = 25;
    pCodecCtxEnc->time_base.num = 1;
    pCodecCtxEnc->pix_fmt = PIX_FMT_YUV420P;

    // set the output parameters (must be done even if no parameters).
    if (av_set_parameters(pFormatCtxEnc, NULL) < 0) {
        return -1;
    }

    dump_format(pFormatCtxEnc, 0, filename, 1);

        if (url_fopen(&pFormatCtxEnc->pb, filename, URL_WRONLY) < 0) {
            fprintf(stderr, "Could not open '%s'\n", filename);
            return -1;
        }

    // write the stream header, if any
    av_write_header(pFormatCtxEnc);

    for ( i = 0; i < 300; i++)
    {
        fread(buf, WIDTH, HEIGHT, fin);
        fread(buf + WIDTH*HEIGHT, WIDTH/2, HEIGHT/2, fin);
        fread(buf + WIDTH*HEIGHT*5/4, WIDTH/2, HEIGHT/2, fin);

        AVPacket pkt;
        av_init_packet(&pkt);

        pkt.flags |= PKT_FLAG_KEY;
        pkt.stream_index= video_st->index;
        pkt.data= buf;
        pkt.size= WIDTH*HEIGHT*3/2;

        // write the compressed frame in the media file
        av_write_frame(pFormatCtxEnc, &pkt);
    }

    // write the trailer, if any
    av_write_trailer(pFormatCtxEnc);

    // free the streams
    for(i = 0; i < pFormatCtxEnc->nb_streams; i++) {
        av_freep(&pFormatCtxEnc->streams[i]->codec);
        av_freep(&pFormatCtxEnc->streams[i]);
    }

    if (!(pOutputFormat->flags & AVFMT_NOFILE)) {
        /* close the output file */
        url_fclose(pFormatCtxEnc->pb);
    }

    /* free the stream */
    av_free(pFormatCtxEnc);

    fclose(fin);

    return 0;
}