st->codec.frame_rate = ap->frame_rate;
st->codec.frame_rate      = ap->frame_rate; st->codec.frame_rate_base = ap->frame_rate_base;
static int video_read_header(AVFormatContext *s,                             AVFormatParameters *ap){    AVStream *st;    st = av_new_stream(s, 0);    if (!st)        return AVERROR_NOMEM;    st->codec.codec_type = CODEC_TYPE_VIDEO;    st->codec.codec_id = s->iformat->value;    /* for mjpeg, specify frame rate */    /* for mpeg4 specify it too (most mpeg4 streams dont have the fixed_vop_rate set ...)*/    if (st->codec.codec_id == CODEC_ID_MJPEG || st->codec.codec_id == CODEC_ID_MPEG4) {        if (ap) {            st->codec.frame_rate = ap->frame_rate;        } else {            st->codec.frame_rate = 25 * FRAME_RATE_BASE;        }    }    return 0;}