High-definition webcasting equipment is divided into three parts to speak of video, audio and upload. Equipment, two main issues, one is to match, one is the price.
One, the video capture device
1, high-definition camera, as a high-definition video source. Selection of cameras need to pay attention to see the output port is HDMI or SDI, with the cable interface match, (here we take HDMI HD transmission as an example), the collection of pixels generally 1920 * 1080P (Ultra HD).
2, video capture card, the high-definition video capture through the usb interface output to the computer. Make sure the interface is HDMI interface (consistent with the camera and cable), and then capture the resolution is generally divided into 60 fps and 30 fps, generally 60 fps corresponds to 1080P, 30 fps corresponds to 720P.
3, high-definition video transmission line, and the camera interface is consistent with the hdmi interface.
Two, sound acquisition equipment
1, audio line to connect the sound source. Hotel venue sound console, give a sound output port, single, monitor road can be, through a long enough (according to the site layout) audio line connected to our live station, as the sound source. Common sound interface has a card dragon head (divided into male and female), large two-core (6.5mm), headphones head (3.5mm), pay attention to the interface match, with a suitable variety of adapters.?
2, sound card. Will receive the sound collection, through the USB transmission to the computer. Sound card selection with noise reduction effect of the sound card. If it is a direct camera receives the sound, it does not need a sound card to do specialized sound acquisition. Direct video capture box will be transmitted together with the camera screen, sound, due to the meeting site is more noisy, generally do not recommend this approach.
Three, uploading equipment
Uploading words here, using an ordinary computer plus third-party software, directly push the stream upload.
1, computer selection. There is no requirement for the computer model, ordinary office laptop can also be, but the configuration should be relatively can. Mainly the following requirements: A, running memory more than 8G. B, more than one USB3.0 interface to ensure the transmission of high-definition video, computer USB3.0 interface color blue, faster transmission speed.
2, network selection, preferably network cable access upstream 8M or more networks, the choice of live software will be pushed to the network video and audio.
Expanded information:
Basic elements of live video broadcasting:
1, bit rate (bitrate)
Bit rate, or bit rate, refers to the unit of time generated by the unit of data bits, the unit of bps (bit per second)
(*Note the difference between bps and B/s, 1B/s=8bps.)
Usually, the bit rate of 720P stream is around 2~4Mbps, and the bit rate of 1080P stream is around 4~8Mbps, and it is the bandwidth requirement for the users, you need at least 2M bandwidth to watch 720P video.
To see 1080P video need at least 4M bandwidth, the current domestic network environment, upstream and downstream rate is not equal, if the anchor to use high-definition video, but also to ensure that the anchor upstream bandwidth is sufficient.
There are two types of encoding, one is called fixed bit rate CBR, which refers to a fixed bit rate for encoding, and the other is called variable bit rate VBR, which refers to a bit rate that varies according to the actual data size for encoding.
2, resolution (resolution)
Resolution refers to the size of the screen, the higher the resolution, the larger the image. In general, in the case of a certain bit rate, the higher the resolution, the worse the video quality.
There are two kinds of resolution, image resolution and display resolution, image resolution refers to the size of the image and display resolution refers to the screen resolution.
For video, there are some fixed-size resolution standards, such as D1 (720×576), 4CIF (704×576), VGA (640×480), SVGA (800×600), VXGA (1600×1200), etc., and later on, for a fixed-ratio (16:9) screen.
Resolution of the representation of the vertical height plus scanning, such as 720P (1280 × 720, progressive scanning), 1080P (1920 × 1080, progressive scanning), 1080I (1920 × 1080, interlaced).
Further back, horizontal pixel descriptions are used, such as 2K (2048×1536 or 2560×1440 or 2560×1600), 4K (4096×2160 or 3840×2160), 8K (7680×4320).
Resolutions below 720P are called SD (around 400 lines, such as 480P), 720P is called HD, 1080P/1080I is called Full HD, and above that is called Ultra HD.
3, frame rate (framerate)
Frame refers to a single picture in the stream, frame rate refers to the number of frames per unit of time in the stream, the unit fps (frame per second). A sudden change in frame rate is most likely to cause a lag in the picture, and a stable, high frame rate ensures a smooth video experience.
Because the human eye has a visual pause effect, for a shorter time difference between the smaller changes in the picture, people will think that the picture is continuous, usually, the video frame rate is stabilized at 30fps or more, people will feel basically smooth, 60fps will make people feel very smooth, but higher than 75fps, the human eye will be less able to detect the smoothness of the improvement.
The frame rate of a movie shown in a movie theater is usually 24 frames per second, but a person still feels smooth. The reason is that the frames of a movie are dynamically fuzzy, and the human eye ignores these fuzzy differences, whereas every frame displayed on a computer is crisp and clear, so the requirements for frame rate on a monitor will be higher than those in a movie theater.
4, packet loss rate (packet loss rate)
Packet loss rate refers to the number of packets lost in transmission as a percentage of the number of packets sent. The larger the packet loss rate, the more the picture stutters, or even no picture at all. Generally speaking, when the packet loss rate exceeds 2%, the screen will show obvious frame dropping.
Checking the packet loss rate is usually done by long ping or tracert (or traceroute), and there are some tools and software that can be used to detect or simulate packet loss, such as iperf, netperf, and so on.
5, delay (delay)
Commonly referred to as the data from the generation to the reception of the process of time consuming, generally refers to the network transmission delay.
There are many factors affecting the network delay, the transmission process has lost packets, gateway conversion slow, slow node processing, etc. may have an impact on the network delay, the network environment, there is an unstable delay, it is very easy to cause frame skipping, frame jamming and so on. Usually, the LAN delay requirement is below 400ms, and the WAN or Internet delay requirement is within 3~5s.