jiffies = (70*FRAME_RATE_BASE/enc->frame_rate) - 1;
jiffies = (70*enc->frame_rate_base/enc->frame_rate) - 1;
static int gif_write_video(AVFormatContext *s,                            AVCodecContext *enc, uint8_t *buf, int size){    ByteIOContext *pb = &s->pb;    GIFContext *gif = s->priv_data;    int jiffies;    int64_t delay;    /* graphic control extension block */    put_byte(pb, 0x21);    put_byte(pb, 0xf9);    put_byte(pb, 0x04); /* block size */    put_byte(pb, 0x04); /* flags */        /* 1 jiffy is 1/70 s */    /* the delay_time field indicates the number of jiffies - 1 */    delay = gif->file_time - gif->time;    /* XXX: should use delay, in order to be more accurate */    /* instead of using the same rounded value each time */    /* XXX: don't even remember if I really use it for now */    jiffies = (70*FRAME_RATE_BASE/enc->frame_rate) - 1;    put_le16(pb, jiffies);    put_byte(pb, 0x1f); /* transparent color index */    put_byte(pb, 0x00);    gif_image_write_image(pb, 0, 0, enc->width, enc->height,                          buf, enc->width * 3, PIX_FMT_RGB24);    put_flush_packet(&s->pb);    return 0;}