ffmpeg 最简单的编码264

     前一篇介绍过用x264编码文件，ffmpeg内部也是用x264编码，这里记录下简单的用ffmpeg的编码
    直接上代码：

onst char* SRC_FILE = "1.mp4";
const char* OUT_FILE = "outfile.h264";

typedef struct X264Context {
    AVClass *pclass;
    x264_param_t    params;
    x264_t *enc;
    x264_picture_t  pic;
    uint8_t *sei;
    int sei_size;
    char *preset;
    char *tune;
    char *profile;
    char *level;
    int fastfirstpass;
    char *wpredp;
    char *x264opts;
    float crf;
    float crf_max;
    int cqp;
    int aq_mode;
    float aq_strength;
    char *psy_rd;
    int psy;
    int rc_lookahead;
    int weightp;
    int weightb;
    int ssim;
    int intra_refresh;
    int bluray_compat;
    int b_bias;
    int b_pyramid;
    int mixed_refs;
    int dct8x8;
    int fast_pskip;
    int aud;
    int mbtree;
    char *deblock;
    float cplxblur;
    char *partitions;
    int direct_pred;
    int slice_max_size;
    char *stats;
    int nal_hrd;
    char *x264_params;
} X264Context;


int main()
{
    FILE *yuv_file = fopen("yuv_file", "ab");
    if (!yuv_file)
        return 0;
    av_register_all();
    AVFormatContext* pFormat = NULL;
    if (avformat_open_input(&pFormat, SRC_FILE, NULL, NULL) < 0)
    {
        return 0;
    }
    AVCodecContext* video_dec_ctx = NULL;
    AVCodec* video_dec = NULL;
    if (avformat_find_stream_info(pFormat, NULL) < 0)
    {
        return 0;
    }
    av_dump_format(pFormat, 0, SRC_FILE, 0);
    video_dec_ctx = pFormat->streams[0]->codec;
    video_dec = avcodec_find_decoder(video_dec_ctx->codec_id);
    if (avcodec_open2(video_dec_ctx, video_dec, NULL) < 0)
    {
        return 0;
    }

    AVFormatContext* pOFormat = NULL;
    AVOutputFormat* ofmt = NULL;
    if (avformat_alloc_output_context2(&pOFormat, NULL, NULL, OUT_FILE) < 0)
    {
        return 0;
    }
    ofmt = pOFormat->oformat;
    if (avio_open(&(pOFormat->pb), OUT_FILE, AVIO_FLAG_READ_WRITE) < 0)
    {
        return 0;
    }
    AVCodecContext *video_enc_ctx = NULL;
    AVCodec *video_enc = NULL;
    video_enc = avcodec_find_encoder(AV_CODEC_ID_H264);
    AVStream *video_st = avformat_new_stream(pOFormat, video_enc);
    if (!video_st)
        return 0;
    video_enc_ctx = video_st->codec;
    video_enc_ctx->profile = FF_PROFILE_H264_HIGH;
    video_enc_ctx->width = video_dec_ctx->width;
    video_enc_ctx->height = video_dec_ctx->height;
    video_enc_ctx->pix_fmt = PIX_FMT_YUV420P;
    video_enc_ctx->time_base.num = 1;
    video_enc_ctx->time_base.den = 25;
    video_enc_ctx->bit_rate = 400000;
    video_enc_ctx->gop_size = 250;
    video_enc_ctx->max_b_frames = 10;
    video_enc_ctx->qmin = 10;
    video_enc_ctx->qmax = 51;
    ((X264Context*)(video_enc_ctx->priv_data))->preset = "superfast";
    ((X264Context*)(video_enc_ctx->priv_data))->tune = "zerolatency";
    if (avcodec_open2(video_enc_ctx, video_enc, NULL) < 0)
    {
        printf("编码器打开失败！\n");
        return 0;
    }


    printf("Output264video Information====================\n");
    av_dump_format(pOFormat, 0, OUT_FILE, 1);
    printf("Output264video Information====================\n");
    avformat_write_header(pOFormat, NULL);
    AVPacket *pkt = new AVPacket();
    av_init_packet(pkt);
    AVFrame *pFrame = avcodec_alloc_frame();
    int ts = 0;
    while (1)
    {
        if (av_read_frame(pFormat, pkt) < 0)
        {
            avio_close(pOFormat->pb);
            av_write_trailer(pOFormat);
            delete pkt;
            return 0;
        }
        if (pkt->stream_index == 0)
        {

            int got_picture = 0, ret = 0;
            ret = avcodec_decode_video2(video_dec_ctx, pFrame, &got_picture, pkt);
            if (ret < 0)
            {
                delete pkt;
                return 0;
            }
            pFrame->pts = ts++;
            if (got_picture)
            {
                AVPacket *tmppkt = new AVPacket;
                av_init_packet(tmppkt);
                int size = video_enc_ctx->width*video_enc_ctx->height * 3 / 2;
                char* buf = new char[size];
                memset(buf, 0, size);
                tmppkt->data = (uint8_t*)buf;
                tmppkt->size = size;
                ret = avcodec_encode_video2(video_enc_ctx, tmppkt, pFrame, &got_picture);
                if (ret < 0)
                {
                    avio_close(pOFormat->pb);
                    delete buf;
                    return 0;
                }
                if (got_picture)
                {
                    printf(".");
                    ret = av_interleaved_write_frame(pOFormat, tmppkt);
                    delete tmppkt;
                    delete buf;
                }
            }
        }

    }
    avcodec_free_frame(&pFrame);
    return 0;
}