Android 5.0 Source code learning (media)

最新推荐文章于 2023-11-24 20:05:46 发布

原创最新推荐文章于 2023-11-24 20:05:46 发布 · 981 阅读

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本文介绍了Nuplayer中ACodec::UninitializedState类的方法onAllocateComponent，该方法通过匹配的编解码器列表来分配组件，并调整线程优先级以确保组件正确加载。若分配失败，则尝试下一个编解码器。

Nuplayer

bool ACodec::UninitializedState::onAllocateComponent(const sp<AMessage> &msg) {

......

for (size_t matchIndex = 0; matchIndex < matchingCodecs.size();
            ++matchIndex) {
        componentName = matchingCodecs.itemAt(matchIndex).mName.string();
        quirks = matchingCodecs.itemAt(matchIndex).mQuirks;

        pid_t tid = androidGetTid();
        int prevPriority = androidGetThreadPriority(tid);
        androidSetThreadPriority(tid, ANDROID_PRIORITY_FOREGROUND);
        status_t err = omx->allocateNode(componentName.c_str(), observer, &node);
        androidSetThreadPriority(tid, prevPriority);

        if (err == OK) {//Get codecs by index in media_codecs.xml
            break;
        } else {
            ALOGW("Allocating component '%s' failed, try next one.", componentName.c_str());
        }

        node = NULL;
    }