pkt->pts = ((int64_t)s->img_number * s1->pts_den * FRAME_RATE_BASE) / (s1->streams[0]->codec.frame_rate * s1->pts_num);
pkt->pts = av_rescale((int64_t)s->img_number * s1->streams[0]->codec.frame_rate_base, s1->pts_den, s1->streams[0]->codec.frame_rate) / s1->pts_num;
static int img_read_packet(AVFormatContext *s1, AVPacket *pkt){    VideoData *s = s1->priv_data;    char filename[1024];    int ret;    ByteIOContext f1, *f;    if (!s->is_pipe) {        if (get_frame_filename(filename, sizeof(filename),                               s->path, s->img_number) < 0)            return -EIO;        f = &f1;        if (url_fopen(f, filename, URL_RDONLY) < 0)            return -EIO;    } else {        f = &s1->pb;        if (url_feof(f))            return -EIO;    }    av_new_packet(pkt, s->img_size);    pkt->stream_index = 0;    s->ptr = pkt->data;    ret = av_read_image(f, filename, s->img_fmt, read_packet_alloc_cb, s);    if (!s->is_pipe) {        url_fclose(f);    }    if (ret < 0) {        av_free_packet(pkt);        return -EIO; /* signal EOF */    } else {        pkt->pts = ((int64_t)s->img_number * s1->pts_den * FRAME_RATE_BASE) / (s1->streams[0]->codec.frame_rate * s1->pts_num);        s->img_number++;        return 0;    }}