getDuration 源码

static jlong IjkMediaPlayer_getDuration(JNIEnv *env, jobject thiz)
{
    jlong retval = 0;
    IjkMediaPlayer *mp = jni_get_media_player(env, thiz);
    JNI_CHECK_GOTO(mp, env, NULL, "mpjni: getDuration: null mp", LABEL_RETURN);

    retval = ijkmp_get_duration(mp);

LABEL_RETURN:
    ijkmp_dec_ref_p(&mp);
    return retval;
}


long ijkmp_get_duration(IjkMediaPlayer *mp)
{
    assert(mp);
    pthread_mutex_lock(&mp->mutex);
    long retval = ijkmp_get_duration_l(mp);
    pthread_mutex_unlock(&mp->mutex);
    return retval;
}

static long ijkmp_get_duration_l(IjkMediaPlayer *mp)
{
    return ffp_get_duration_l(mp->ffplayer);
}

long ffp_get_duration_l(FFPlayer *ffp)
{
    assert(ffp);
    VideoState *is = ffp->is;
    if (!is || !is->ic)
        return 0;

    int64_t duration = fftime_to_milliseconds(is->ic->duration);
    if (duration < 0)
        return 0;

    return (long)duration;
}

#define fftime_to_milliseconds(ts) (av_rescale(ts, 1000, AV_TIME_BASE))