2015年3月4日
By 1月时特约编辑
专题文章

2015年实时视频编码器买家指南

恭喜你，你买了一个实时编码器. In 2014, Ooyala 发布调查结果 showing that live videos are watched, on average, 11 times longer than VOD videos. 看看你的演讲, 网络研讨会, 或其他生产现场是一个伟大的举动, 如果你刚刚开始购买编码器, 你来对地方了. 在设定了一些基础之后, I’ll run through the questions that you should ask when shopping for an encoder in 2015. 一路走来, I’ll identify the major categories of products you should be considering and discuss some features you should use to differentiate products within each category.

最基本的

You probably already know the basics, but they always bear repeating. The first step is to identify the number of streams and formats you’ll need the encoder to produce. There are two basic live streaming paradigms: the first is to encode all streams onsite and push them out to your streaming server. The second is to produce a single high-quality stream onsite and push that to a cloud transcoding facility to create your adaptive streams. 如果你在现场制作多个流, 你需要一个非常强大的编码器, 特别是如果你要支持多种格式. 这一要求限制了你的购买选择. 如果您正在生成单个流, either for single file delivery to your viewers or for live transcoding, 您将有更多的编码器可供选择.

一旦你知道了流和格式计数, 您应该确定流的辅助需求, 包括数字版权管理, 标题支持, 广告插入, 商业广告噪音减少法案支持, 等等....... 在很大程度上, 只有高端编码器提供这些功能, 所以如果你需要的话, make them the first items you check for when considering an encoder.

接下来，确定所需的相机或混频器相关的连接. This is usually HD-SDI or HDMI, but could also include DV or analogue. Most encoder manufacturers offer multiple models differentiated by their I/O, 所以在选择订购的具体型号时要密切注意.

Also check the delivery side of the equation—make sure your encoding gear can connect to your streaming server. If you’re streaming to an RTMP server, make sure the encoder supports RTMP; surprisingly, not all do. 如果你使用的是第三方服务, 检查任何推荐的编码器的网站或论坛, 或者任何你应该避免的. 特别是, 转播画面 has developed a range of hardware and software products for deployment on its platform, 所以如果你是在转播画面平台上出售游戏, 你应该先看看它的直播编码产品. 另外，如果你正在使用 Wowza 媒体引擎, 或者类似的流媒体服务器, 查看公司的论坛，看看是哪一个, 如果有任何, 编码器引起了一些问题, 哪些是推荐的.

购买高端编码器

If you need an encoder that can produce multiple streams in multiple formats onsite, 或者需要支持DRM, 标题, 诸如此类, 你需要一个或多个高端编码器，价格可能为10美元,000及以上. Most suppliers in this category are mature companies that have been serving the broadcast market for years, 你应该有多种选择.

From a feature perspective, products in the category are fairly similar. One relevant difference is whether the system is software- or chip-based. Software-based systems run on industry-standard hardware and can be updated easily for new formats like H.265, which should start to become relevant as a delivery format in 2015. Chip-based systems run on dedicated (usually) codec-specific silicon that can’t be updated, but are usually cheaper than software-based systems because the application-specific silicon is more efficient. 如果你知道要用H.在接下来的几年里，可能越便宜越好. 如果你想要去HEVC, 软件系统提供的灵活性可能物有所值.

You should also consider the availability of cloud encoding capabilities to supplement your on-premise encoder, 如果只是为了偶尔的生产需求高峰. 在这方面, the ability to use the same presets and workflows can save hours of testing and debugging over a third-party encoder.

If you don’t need these high-end features, you have much more flexibility in your purchase decision. So now let’s discuss the questions you should ask before writing the check.

免费对你有用吗?

如果你已经有了电脑和视频采集卡, 几个免费的解决方案中的一个可能对你有用. 一个是 Adobe Flash Live Media Encoder, which has been used very widely over the years. 如前所述, if you’re broadcasting via a live streaming service provider such as 转播画面, Ustream, or YouTube 首先，检查供应商是否提供免费的编码程序. 而一些免费程序可能不全功能, 它们是坚实的起点, and many vendors offer an upgrade path to versions of the program that do more. 再一次。, 转播画面 offers a free version of its highly competent video mixer/encoder Studio for all producers streaming through the 转播画面 platform, and all 转播画面 producers should check it out before buying a third-party video mixer or encoder.

会有以太网还是Wi-Fi?

If you’ll be broadcasting from a fixed location with connectivity, any encoder will do. 另一方面, if you’ll be broadcasting from different locations that might not have Ethernet or Wi-Fi, 你需要一个具有4G功能的编码器, 它们有多种形状和大小.

例如, 松下 has a range of cameras with USB ports that can host an Ethernet card, Wi-Fi, or 3G/4G modem. All of the cameras have two codecs and can encode a broadcast-quality stream saved on one SD card and produce another encoded stream for live transmission or storage to a second SD card. These cameras let you monitor encoding and transmission in the viewfinder, providing an integrated interface that enables one operator to shoot as well as manage the streaming operation.

如果你的摄像机没有4G功能, multiple vendors offer on-camera encoders with USB ports for 3G/4G modems. Many vendors also offer bonding solutions that allow you to deploy multiple 3G/4G modems from one or more telecom providers. You can use these to aggregate the signal for higher bandwidth transmissions, 提供载波冗余, 或两个.

下一个页面