IikPlayer设置参数超时解析

查看入口函数\ijkplayer\ijkmedia\ijkplayer\android\ijkplayer_jni.c

JNIEXPORT jint JNI_OnLoad(JavaVM *vm, void *reserved)
{
    JNIEnv* env = NULL;

    g_jvm = vm;
    if ((*vm)->GetEnv(vm, (void**) &env, JNI_VERSION_1_4) != JNI_OK) {
        return -1;
    }
    assert(env != NULL);

    pthread_mutex_init(&g_clazz.mutex, NULL );

    // FindClass returns LocalReference
    IJK_FIND_JAVA_CLASS(env, g_clazz.clazz, JNI_CLASS_IJKPLAYER);
    (*env)->RegisterNatives(env, g_clazz.clazz, g_methods, NELEM(g_methods) );

    ijkmp_global_init();
    ijkmp_global_set_inject_callback(inject_callback);

    FFmpegApi_global_init(env);

    return JNI_VERSION_1_4;
}

我们看到注册了方法集合g_methods中的函数_setOption
- 在java代码层的native有个native _setOption

查看方法实现 IjkMediaPlayer_setOptionLong

static void
IjkMediaPlayer_setOptionLong(JNIEnv *env, jobject thiz, jint category, jobject name, jlong value)
{
    MPTRACE("%s\n", __func__);
    IjkMediaPlayer *mp = jni_get_media_player(env, thiz);
    const char *c_name = NULL;
    JNI_CHECK_GOTO(mp, env, "java/lang/IllegalStateException", "mpjni: setOptionLong: null mp", LABEL_RETURN);

    c_name = (*env)->GetStringUTFChars(env, name, NULL );
    JNI_CHECK_GOTO(c_name, env, "java/lang/OutOfMemoryError", "mpjni: setOptionLong: name.string oom", LABEL_RETURN);

    ijkmp_set_option_int(mp, category, c_name, value);

LABEL_RETURN:
    if (c_name)
        (*env)->ReleaseStringUTFChars(env, name, c_name);
    ijkmp_dec_ref_p(&mp);
}

继续追具体调用ijkmp_set_option_int(mp, category, c_name, value)

ijkmedia\ijkplayer\ijkplayer.c#180

void ijkmp_set_option_int(IjkMediaPlayer *mp, int opt_category, const char *name, int64_t value)
{
    assert(mp);

    // MPTRACE("%s(%s, %"PRId64")\n", __func__, name, value);
    pthread_mutex_lock(&mp->mutex);
    ffp_set_option_int(mp->ffplayer, opt_category, name, value);
    pthread_mutex_unlock(&mp->mutex);
    // MPTRACE("%s()=void\n", __func__);
}

继续跟进ffp_set_option_int(mp->ffplayer, opt_category, name, value) ijkmedia\ijkplayer\ff_ffplay.c#4169

void ffp_set_option_int(FFPlayer *ffp, int opt_category, const char *name, int64_t value)
{
  if (!ffp)
      return;

  AVDictionary **dict = ffp_get_opt_dict(ffp, opt_category);
  av_dict_set_int(dict, name, value, 0);
}

这里调用了ffmpeg的参数设置av_dict_set_int

ffmpeg\libutil\dict.c#147

//#147. 
int av_dict_set_int(AVDictionary **pm, const char *key, int64_t value,
                int flags)
{
    char valuestr[22];
    snprintf(valuestr, sizeof(valuestr), "%"PRId64, value);
    flags &= ~AV_DICT_DONT_STRDUP_VAL;
    return av_dict_set(pm, key, valuestr, flags);
}

//#70
int av_dict_set(AVDictionary **pm, const char *key, const char *value,
                int flags)
{
    AVDictionary *m = *pm;
    AVDictionaryEntry *tag = NULL;
    char *oldval = NULL, *copy_key = NULL, *copy_value = NULL;

    if (!(flags & AV_DICT_MULTIKEY)) {
        tag = av_dict_get(m, key, NULL, flags);
    }
    if (flags & AV_DICT_DONT_STRDUP_KEY)
        copy_key = (void *)key;
    else
        copy_key = av_strdup(key);
    if (flags & AV_DICT_DONT_STRDUP_VAL)
        copy_value = (void *)value;
    else if (copy_key)
        copy_value = av_strdup(value);
    if (!m)
        m = *pm = av_mallocz(sizeof(*m));
    if (!m || (key && !copy_key) || (value && !copy_value))
        goto err_out;

    if (tag) {
        if (flags & AV_DICT_DONT_OVERWRITE) {
            av_free(copy_key);
            av_free(copy_value);
            return 0;
        }
        if (flags & AV_DICT_APPEND)
            oldval = tag->value;
        else
            av_free(tag->value);
        av_free(tag->key);
        *tag = m->elems[--m->count];
    } else if (copy_value) {
        AVDictionaryEntry *tmp = av_realloc(m->elems,
                                            (m->count + 1) * sizeof(*m->elems));
        if (!tmp)
            goto err_out;
        m->elems = tmp;
    }
    if (copy_value) {
        m->elems[m->count].key = copy_key;
        m->elems[m->count].value = copy_value;
        if (oldval && flags & AV_DICT_APPEND) {
            size_t len = strlen(oldval) + strlen(copy_value) + 1;
            char *newval = av_mallocz(len);
            if (!newval)
                goto err_out;
            av_strlcat(newval, oldval, len);
            av_freep(&oldval);
            av_strlcat(newval, copy_value, len);
            m->elems[m->count].value = newval;
            av_freep(&copy_value);
        }
        m->count++;
    } else {
        av_freep(&copy_key);
    }
    if (!m->count) {
        av_freep(&m->elems);
        av_freep(pm);
    }

    return 0;

err_out:
    if (m && !m->count) {
        av_freep(&m->elems);
        av_freep(pm);
    }
    av_free(copy_key);
    av_free(copy_value);
    return AVERROR(ENOMEM);
}