如何通过OpenHarmony系统中集成的ffmpeg库和NAPI机制，实现更多 精华

 "myffmpegsys": {
             "path": "myffmpegsys",
            "name": "myffmpegsys"
        },

"parts":{
            "myffmpegsys:myffmpegpart":{},
     "ace:ace_engine_standard":{},
     ......
  }

import("//build/ohos.gni")
ohos_shared_library("myffmpegdemo") {
  include_dirs = [
    "//foundation/ace/napi/interfaces/kits",
    "//myffmpegsys/myffmpegpart/myffmpegdemo/include",
    "//third_party/ffmpeg",
  ]
  sources = [
    "myffmpegdemo.cpp",
    "ffmpeg_utils.cpp",
  ]
  public_deps = [
    "//foundation/ace/napi:ace_napi",
    "//third_party/ffmpeg:libohosffmpeg"
  ]
  external_deps = [
    "hiviewdfx_hilog_native:libhilog",
  ]
  relative_install_dir = "module"
  subsystem_name = "myffmpegsys"
  part_name = "myffmpegpart"
}

/***********************************************
 * Module export and register
 ***********************************************/
static napi_value registerMyffmpegdemo(napi_env env, napi_value exports)
{
    static napi_property_descriptor desc[] = {
        DECLARE_NAPI_FUNCTION("videoCute", videoCute),
        DECLARE_NAPI_FUNCTION("videoToAacH264", videoToAacH264),
    };
    napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc);
    return exports;
}

static void executeVideoCute(napi_env env, void* data) {
    VideoCuteAddOnData *addonData = (VideoCuteAddOnData *) data;
    //调用视频剪切的功能
    addonData->result = FfmpegUtils::videoCute((const char*)addonData->args0.c_str(), \
                                     addonData->args1, \
                                    addonData->args2, \
                                    (const char*)addonData->args3.c_str());
}

//初始化上下文
    ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0);
    if (ret < 0) {
        ERROR_BUF(ret);
        HiLog::Error(LABEL, "gyf avformat_open_input error = %{public}s", errbuf);
        return ret;
    }
    ret = avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, out_filename);
    if (ret < 0) {
        ERROR_BUF(ret);
        HiLog::Error(LABEL, "gyf avformat_alloc_output_context2 error = %{public}s", errbuf);
        goto end;
    }
     ofmt = ofmt_ctx->oformat;

//创建流以及参数拷贝
    for (int i = 0; i < (int)ifmt_ctx->nb_streams; i++) {
        in_stream = ifmt_ctx->streams[i];
        AVStream *out_stream = avformat_new_stream(ofmt_ctx, NULL);
        if (!out_stream) {
            ret = AVERROR_UNKNOWN;
            goto end;
        }
        avcodec_parameters_copy(out_stream->codecpar, in_stream->codecpar);
        out_stream->codecpar->codec_tag = 0;
     }

//打开输出文件
    ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
    if (ret < 0) {
        ERROR_BUF(ret);
        HiLog::Error(LABEL, "gyf avio_open error = %{public}s", errbuf);
        goto end;
    }    // 写头信息
    ret = avformat_write_header(ofmt_ctx, NULL);
    if (ret < 0) {
        ERROR_BUF(ret);
        HiLog::Error(LABEL, "gyf avformat_write_header error = %{public}s", errbuf);
        goto end;
     }

 //跳转到指定帧
     ret = av_seek_frame(ifmt_ctx, -1, start_seconds * AV_TIME_BASE, AVSEEK_FLAG_ANY);
    if (ret < 0) {
        ERROR_BUF(ret);
        HiLog::Error(LABEL, "gyf av_seek_frame error = %{public}s", errbuf);
        goto end;
     }

//读取数据
        ret = av_read_frame(ifmt_ctx, &pkt);
        if (ret < 0) {
            break;
        }


        in_stream = ifmt_ctx->streams[pkt.stream_index];
        out_stream = ofmt_ctx->streams[pkt.stream_index];


        // 时间超过要截取的时间，就退出循环
        if (av_q2d(in_stream->time_base) * pkt.pts > end_seconds) {
            av_packet_unref(&pkt);
            break;
         }

 //写文件尾信息
  ret = av_write_trailer(ofmt_ctx);

cutevideo() {
        globalThis.isCuteSuccess = false;
        console.log('gyf cutevideo');
        myffmpegdemo.videoCute(this.src, this.startTime, this.endTime, this.srcOut,
            function (result) {
                console.log('gyf cutevideo callback result = ' + result);
                globalThis.showPrompt('videoCute finished!');
                if (0 === result) {
                    globalThis.isCuteSuccess = true;
                } else {
                    globalThis.isCuteSuccess = false;
                }
            }
        );
},