static void compute_frame_duration(int *pnum, int *pden, AVFormatContext *s, AVStream *st,
static void compute_frame_duration(int *pnum, int *pden, AVStream *st,
static void compute_frame_duration(int *pnum, int *pden,                                   AVFormatContext *s, AVStream *st,                                    AVCodecParserContext *pc, AVPacket *pkt){    int frame_size;    *pnum = 0;    *pden = 0;    switch(st->codec.codec_type) {    case CODEC_TYPE_VIDEO:        *pnum = st->codec.frame_rate_base;        *pden = st->codec.frame_rate;        if (pc && pc->repeat_pict) {            *pden *= 2;            *pnum = (*pnum) * (2 + pc->repeat_pict);        }        break;    case CODEC_TYPE_AUDIO:        frame_size = get_audio_frame_size(&st->codec, pkt->size);        if (frame_size < 0)            break;        *pnum = frame_size;        *pden = st->codec.sample_rate;        break;    default:        break;    }}