视频会议的迭代方向是打造更好的“临场感”

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"2020年，突如其来的新冠肺炎疫情改变了许多人的生活和工作方式。疫情之下，RTC（实时音视频）产品受到越来越多的关注，用户对产品的质量也有着越来越高的要求。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"“以往传统视频会议产品更侧重于大企业内部使用，形态上专用设备和PC端居多。疫情让所有企业，特别是中小微企业，对远程办公，视频会议产品有了广泛的需求，使用场景与之前相比也更为复杂，不再局限于办公场所的开会，而是要求能够随时随地便捷接入通讯，终端也从企业级设备、PC向移动电话延伸。”近日，腾讯会议高级工程师赵珺接受InfoQ采访，就音视频的发展现状、不足以及改进方向等话题展开讨论。他表示，视频会议产品的迭代方向主要是针对这类复杂场景打造更好的“临场感”。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"5月29日，赵珺将于QCon 全球软件开发大会（北京站）的《音视频体验提升实战》专题中，带来“音视频QoE优化工作的难点与挑战”的分享。希望借本次分享系统阐述RTC领域质量工作所面临的问题及难点，并结合在腾讯会议产品上的实践来介绍利用现网数据优化用户QoE的思考与成果。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"以下是InfoQ与赵珺的对话纪要："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"InfoQ：后疫情时代，远程会议工作模式越来越被接纳，而随着需求激增，视频会议产品也需要推陈出新，在您看来，从新冠疫情最初爆发至今，像视频会议这类音视频产品的更新迭代主要侧重在哪些方面？"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"赵珺：以往传统视频会议产品更侧重于大企业内部使用，形态上专用设备和PC端居多。去年年初疫情的突然爆发，让所有企业，特别是中小微企业对于远程办公，视频会议产品有了广泛的需求，使用场景与之前相比也更为复杂，不再局限于办公场所的开会，而是要求能够随时随地的便捷接入通讯，终端也从企业级设备，PC向移动电话延伸。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"视频会议产品的迭代方向主要是针对这类复杂场景打造更好的“临场感”。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"首先从技术上说，会利用更优秀的网络抗性策略，更强大的语音降噪、回声消除能力等技术降低使用环境复杂化所带来的影响。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"其次，针对不同的客户场景，如何贴近真实开会体验也是一个比较重要的问题，比如针对隐私需求的背景虚化能力，针对重要会议场景的等候室能力，针对交流讨论场景的白板能力，针对培训场景的录制能力等，都是让用户一方面体验线上会议的优势，另一方面降低无法现场交流的不便。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"InfoQ：您如何看待现阶段音视频对质量的要求？能否结合音视频体验的发展趋势展开聊聊。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"赵珺：与单纯的文字相比，音视频是人类视觉和听觉可以直接触达的媒体，人们对于音视频的主观评价会更为直接，对音视频产品的体验要求也是逐步提高的。以视频为例，几十年前，一个小小的黑白电视就能满足需求，而后的彩色电视，高清格式，4K格式， HDR等技术升级都在提升着对于视频体验的心理预期。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"所以说人们对于音视频的体验需求是没有上限的，但是却有下限，那就是保持信息的有效传递。设想一下，如果出现火灾，打不通电话，或打通了说不清楚信息，后果将是灾难性的。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"InfoQ：面对音视频服务的不同发展阶段，后台技术支撑框架发生了什么样的变化？"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"赵珺：互联网音视频业务大体可分为点播，直播，RTC三个阶段。首先是点播业务，比如我们常用追剧的腾讯视频、爱奇艺更多的是关注视频流的快速送达，所以后台上多广泛使用CDN节点；"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"其次是直播业务，在点播业务的基础之上，为追求清晰度与流畅度体验的平衡，往往还会引入转码服务器，对于传输协议也有较多的个性化需求，需要后台来配合处理；"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"最后是RTC业务，与前两者相比，其对于传输RTT的要求会更高，后台结构也相对更复杂，会有流控，房间管理，混音等不同的服务类型来共同工作。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"InfoQ：能否介绍下目前音视频产品的质量工作流程一般是怎么样的？"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"赵珺：以我们为例，目前的工作流程主要分为上线前测试和上线后质量管理两个部分。上线前会针对技术优化的一些点来针对性进行评测，评测标准主要参考了ITU， 3GPP这些组织的一些音视频相关国际标准。特性上线后，会通过产品的灰度策略，来进行A\/B Test 评估优化是否是正向的。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"我们还有多维度的大盘质量报表，借助大量用户数据来评估产品质量的变化趋势，以此来发现问题和持续改进。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"InfoQ：像直播中碰到卡顿、实时音视频通话延迟等情况，一般的解决方法是什么？随着用户体验要求越来越高，互动性也不断加大，对你们来说，这里面的挑战也会越来越大，能否展开介绍下这过程中面临的技术问题和挑战？"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"赵珺：网络带宽是有限的，直播卡顿，语音延迟这些问题多数时候是带宽竞争下所产生的结果。应该从两个维度来考虑解决。第一是编码器、传输协议是否有优化的空间，压缩码流体积，减少不必要的传输开销是根本。如果编码器和协议的选择已经相对较优了，下一步可以尝试的方案就是一个做取舍的策略问题，高清、流畅、低延迟三者不可兼得，应当根据业务场景做出必要的取舍。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"所以这里最主要的挑战应该是编码器的优化，传输协议的优化和带宽探测几个方面。高效编码能让码流更小，高效传输能让带宽浪费更低，准确预测带宽能让分配策略更合理。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"InfoQ：怎么利用用户数据确定音视频产品的改进方向？能否结合实际案例跟我们介绍下？"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"赵珺：为了提升用户体验，腾讯会议引入了媒体代理的架构，由分布在全球的代理节点来为用户提供“就近进入”的服务。如何评价用户接入分配的合理性是一个困扰团队的问题。我们通过对现网QoE用户数据的分析，不仅发现了某地运营商机房的问题， 还得出“最近接入” 并非 “最优接入” 的结论，指导全球接入调度的优化。这个案例也会在本次大会演讲上分享。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"InfoQ：据您观察，现在的音视频产品还存在哪些不足？未来音视频产品有哪些可能的改进方向？"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"赵珺：现有音视频产品是个比较大的命题，受限经验，不敢妄谈。 还是说一下比较了解的RTC业务。从体验角度上来说，RTC的追求目标是“身前1米”的面对面交流的体验，现在很多时候还是难以满足的。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"伴随着5G时代的到来，未来音视频产品会对沉浸式体验的需求将更强，VR、AR一类的技术也会是音视频产品新的载体，因此对于编码压缩，传输，视频高效转码，视频处理，语音降噪等技术都将会有更高的要求。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"InfoQ：总的来看，面对前面提到的问题和挑战，您认为这里边需要什么样的体验质量优化体系？"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"赵珺：音视频体验是技术、人的生理、心理多因素共同作用的结果。音视频体验的评价不单是工业界关心的问题，也是学术界的研究热点之一。现有评价体系局限性还很强，所以对于评价方法的探索是质量优化体系建设最为重要的一环。另一方面，建立完备的，可以覆盖不同用户设备，不同用户场景的质量数据体系也是质量优化建设的努力方向。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"InfoQ：在您看来，除了技术方面，QoE是否也属于管理问题？"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"赵珺：答案是肯定的，QoE本质是一个预期管理的问题，当技术无法满足预期时，最好的方法是降低用户预期，比如在网络差时的一些告知tips, 会起到很好的效果。当然，有些场景下的用户预期管理可能比技术本身难度更高。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"InfoQ：最后，能否说说咱们对未来音视频业务体验的规划方向是怎么样的？"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"赵珺：质量管理方面，除了对于评价标准的持续探索外，未来我们会投入更多的精力在实时监控，问题发现上，为用户使用腾讯会议提供更高级别的质量保障；"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"音视频技术上，相关团队也在加大对于音频降噪，回声消除，网络传输优化，视频编解码等技术方向的投入，在为会议产品服务的同时，也将成果输出给其他领域产品。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"采访嘉宾介绍"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"赵珺，腾讯会议高级工程师，研究生毕业后先后于华为和腾讯任职。在腾讯6年多的时间里，历经QQ音视频，互动直播SDK，游戏语音引擎，腾讯无线投屏，腾讯会议多个实时音视频产品的质量保证和优化工作，在RTC产品测试和基于QoE的监控分析方面有丰富的经验。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"活动推荐"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"赵珺将在今年 5 月 29-31 日举办的 QCon 全球软件开发大会（北京站）「音视频体验提升实战」专场，发布《音视频QoE优化工作的难点与挑战》的演讲，将系统阐述 RTC 领域质量工作所面临的问题及难点，并结合在腾讯会议产品上的实践来介绍利用现网数据优化用户 QoE 的思考与成果。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"QCon大会北京站汇聚 150+ 演讲嘉宾，同时设立 29 个热点技术专场包括 Serverless、Flutter、DDD、音视频、云原生、智能金融、大数据、数字化转型、人工智能等，内容源于实践并面向社区。【扫码】或"},{"type":"link","attrs":{"href":"https:\/\/qcon.infoq.cn\/2021\/beijing\/schedule?utm_source=infoq&utm_medium=article&utm_campaign=10&utm_term=0514&utm_content=banner","title":"xxx","type":null},"content":[{"type":"text","text":"点此"}]},{"type":"text","text":"了解更多。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"今天是大会门票"},{"type":"text","marks":[{"type":"color","attrs":{"color":"#F5222D","name":"red"}}],"text":" 9 "},{"type":"text","text":"折特惠倒计时最后 1 天，现在购票立减"},{"type":"text","marks":[{"type":"color","attrs":{"color":"#F5222D","name":"red"}}],"text":" 880 "},{"type":"text","text":"元。购票欢迎联系票务小姐姐 Doris ：17310043226（电话同微信）"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.infoq.cn\/resource\/image\/b1\/2b\/b13ee664ebe4efef0b7e2cf8d497c42b.jpeg","alt":null,"title":"","style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}}]}