How to mention real image instead of dummy image in ffmpeg api-example.c

Question

Hi,

I am using video_encode_example function from api-example.c of ffmpeg, which basically creates 25 dummy images and encodes into a one second video. How ever i am unable to mention real images instead of dummy ones. If any one know how to do this for xcode objective C, pl submit a reply. Below is the function

/* * 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");

}

Regards