如何在ffmpeg中提供真實圖像而不是僞圖像api-example.c

我正在使用video_encode_example函數從api-example.c FFmpeg，基本上創建25個虛擬圖像和編碼成一秒鐘的視頻。我怎麼都無法提到真實的圖像，而不是虛擬的。如果有人知道如何爲xcode目標C執行此操作，請提交回復。下面是功能如何在ffmpeg中提供真實圖像而不是僞圖像api-example.c

/* 
* Video encoding example 
*/ 
static void video_encode_example(const char *filename) 
{ 
    AVCodec *codec; 
    AVCodecContext *c= NULL; 
    int i, out_size, size, x, y, outbuf_size; 
    FILE *f; 
    AVFrame *picture; 
    uint8_t *outbuf, *picture_buf; 

    printf("Video encoding\n"); 

    /* find the mpeg1 video encoder */ 
    codec = avcodec_find_encoder(CODEC_ID_MPEG1VIDEO); 
    if (!codec) { 
     fprintf(stderr, "codec not found\n"); 
     exit(1); 
    } 

    c= avcodec_alloc_context(); 
    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; 

    /* open it */ 
    if (avcodec_open(c, codec) < 0) { 
     fprintf(stderr, "could not open codec\n"); 
     exit(1); 
    } 

    f = fopen(filename, "wb"); 
    if (!f) { 
     fprintf(stderr, "could not open %s\n", filename); 
     exit(1); 
    } 

    /* alloc image and output buffer */ 
    outbuf_size = 100000; 
    outbuf = malloc(outbuf_size); 
    size = c->width * c->height; 
    picture_buf = malloc((size * 3)/2); /* size for YUV 420 */ 

    picture->data[0] = picture_buf; 
    picture->data[1] = picture->data[0] + size; 
    picture->data[2] = picture->data[1] + size/4; 
    picture->linesize[0] = c->width; 
    picture->linesize[1] = c->width/2; 
    picture->linesize[2] = c->width/2; 

    /* encode 1 second of video */ 
    for(i=0;i<25;i++) { 
     fflush(stdout); 
     /* prepare a dummy image */ 
     /* Y */ 
     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(picture_buf); 
    free(outbuf); 

    avcodec_close(c); 
    av_free(c); 
    av_free(picture); 
    printf("\n"); 
}

來源

2010-03-26 Mohan

-1

我沒有測試，但可能是，如果你捕捉YUV420P格式的圖像可以點圖像 - >數據[0]您捕捉字節的指針。

picture->data[0] = picture_buf; //put your data here, remove the dummy data insertion

來源

2013-03-02 05:57:56 StarDust

@Mohan你可以做這個問題的狀態？ – learner 2014-01-31 17:43:42

如何在ffmpeg中提供真實圖像而不是僞圖像api-example.c

回答

相關問題