评论:视频的Shavano 4K HEVC视频编码器

2018年初, I received an email from the people on the Videon team letting me know that they were using the technique I’d outlined in an 早些时候H.264硬件编码器文章, and that they were keen to get my thoughts on their new 4K HEVC encoder, the Shavano (下面的图1). I had wanted to do more testing with HEVC encoders to see if the hype over compression quality over lower bitrates was justified.

图1. Videon Shavano

HEVC和4K

For my webcasting business, the majority of broadcasts are done at 1280x720/30p between 2.5和5Mbps，从1920x1080/59的视频信号下采样.94p. 像这样, I’m not yet at a point where my clients (or their audiences) need 4K resolution for their live streams. However, the capability to use HEVC compression over slower 网works (e.g.(3G/4G保税解决方案)非常有吸引力.

The difficulty with HEVC for webcasting is the lack of decoder availability across desktop web browsers and smartphones. While iOS 11 or higher devices have had HEVC decoding capabilities since the iPhone 7 or the 2017 iPad Pro, Android 5.0及更高版本的设备可能不始终支持HEVC播放.

像这样, my workflow would need to transcode one high-quality HEVC source stream to one or more H.264流播放. For this task, I use Wowza Streaming Engine to transcode a live HEVC source to H.264年版. This process would give me the benefits of HEVC compression with a lower bandwidth requirement on site, 并提供可玩的H.264流为所有目标受众.

Shavano I/O概述

以满足HEVC日益增长的加工要求, Shavano采用了强大的高通骁龙820处理器, 并具有以下输入(图2), 下图):

• HDMI 1.4输入高达2160p30:如果你想利用4K分辨率, 您需要通过HDMI提供输入信号.
• 3G-SDI input up to 1080p60: You can use the SDI input for resolutions below 4K. While there is no pass-through output for the SDI input, there is an HDMI monitor out.
• USB 3.0 interface for recording: Connect USB storage devices to record archives of live streams.
• 3.5mm Analog Audio input: If the program audio isn’t being carried over HDMI or SDI, 您可以通过此输入路由模拟音频.
• 10/100/1000以太网(RJ-45), Power over Ether网 (PoE): One of my favorite features of the Shavano is the ability to power the unit from the Ether网 cable. You will need a 网work switch capable of supplying power from the Ether网 port. 你可以用不到100美元的价格找到可靠的带PoE的网络交换机.
• 用于记录的SD插槽:位于设备的前面, SD插槽也可以用于本地录制(参见 图1).

图2. 沙瓦诺的后面

对于输入分辨率，Shavano支持以下内容:

• 3840x2160p30, p25, p24
• 1920 x1080p60 p59.94, p30, p29.97, p25
• 1280 x720p60 p59.94, p50

用于实时流的输出分辨率, you can use the same input resolutions and frame rates listed earlier as well as these:

• 960x540p
• 720x380p
• 640x360p
• 480x270p
• 320x180p

Note that if you’re still using an interlaced signal in your video production (e.g., 1080i59.94), the Shavano will not be able to directly process the input signal. You will need to use a separate deinterlacer/converter such as the Decimator Design MD-DUCC (Multi-Definition Down Up Cross Converter) to supply a progressive signal to the Shavano.

管理Shavano

You set up and modify the Shavano’s settings via a browser-based management GUI running directly on the Shavano. 默认情况下, the Shavano’s 网working interface is using DHCP to automatically grab an IP address and DNS settings from the local 网work. The Shavano’s IP address can be located using the Videon Discovery desktop application that can be downloaded from videon-central.com/ resources.com，在发现应用程序标题下. 在安装并运行应用程序之后, make sure your computer is connected to the same 网work as the Shavano. 您网络上的任何Shavano单元都将显示(下面的图3).

图3. Shavano Discovery应用程序

There is no security enabled on the Shavano with default factory settings. You can open a browser window for the Shavano directly from the Discovery application. Shavano的主屏幕，编码器控制(下面的图4)，显示当前的流媒体和录制状态. You can select the HDMI/SDI/audio input in the AV Input Type combo box. If there is a compatible video signal provided on the selected input, 输入分辨率将显示分辨率和帧率.

图4. 编码器控制

固件更新

Before configuring compression settings and output/recording destinations, I highly recommend navigating to the Advanced page and clicking the Check for Update button in the Firmware Update section (下面的图5). During 2018, several updates were released that added new features and fixed bugs.

图5. “高级”页面的“固件更新”部分