if (end_time != MAXINT64) {
if (end_time != MININT64) {
static void av_update_stream_timings(AVFormatContext *ic){    int64_t start_time, start_time1, end_time, end_time1;    int i;    AVStream *st;    start_time = MAXINT64;    end_time = MININT64;    for(i = 0;i < ic->nb_streams; i++) {        st = ic->streams[i];        if (st->start_time != AV_NOPTS_VALUE) {            start_time1= av_rescale_q(st->start_time, st->time_base, AV_TIME_BASE_Q);            if (start_time1 < start_time)                start_time = start_time1;            if (st->duration != AV_NOPTS_VALUE) {                end_time1 = start_time1                          + av_rescale_q(st->duration, st->time_base, AV_TIME_BASE_Q);                if (end_time1 > end_time)                    end_time = end_time1;            }        }    }    if (start_time != MAXINT64) {        ic->start_time = start_time;        if (end_time != MAXINT64) {            ic->duration = end_time - start_time;            if (ic->file_size > 0) {                /* compute the bit rate */                ic->bit_rate = (double)ic->file_size * 8.0 * AV_TIME_BASE /                     (double)ic->duration;            }        }    }}