A, video acquisition equipment
1, HD camera, as HD video source. When choosing a camera, you should pay attention to whether the output port is HDMI or SDI, which matches the wired interface. (Let's take HDMI high-definition transmission as an example. ) The pixels collected are generally 1920* 1080P (Ultra HD).
2. Video acquisition card, which collects high-definition video and outputs it to the computer through usb interface. Make sure that the interface is HDMI (consistent with the camera and wire), and then the acquisition resolution is generally divided into 60 frames and 30 frames, with 60 frames corresponding to 1080P and 30 frames corresponding to 720P.
3. The high-definition video transmission line is consistent with the camera interface and hdmi interface.
Second, the sound acquisition equipment
1, the audio cable is connected to the audio source. The sound control station in the hotel venue is equipped with a sound output port, which can be mono or monitoring channel. It is connected to our live broadcast station through a long enough audio line (depending on the layout of the website) as a sound source. Common sound interfaces are card tap (male and female), large dual core (6.5 mm) and earphone head (3.5 mm). Pay attention to the matching of interfaces and bring appropriate adapters. ?
2. Sound card. Collect the received sound and transmit it to the computer through USB. Sound card Choose a sound card with noise reduction effect. If it is a direct camera, you don't need a sound card for special sound collection. The direct video capture box transmits the video and sound of the camera together, which is generally not recommended because of the noisy meeting site.
Third, upload equipment.
If you upload it, you can use ordinary computers and third-party software to upload it directly.
1, computer selection. There is no requirement for the computer model, and ordinary office laptops are also acceptable, but the configuration should be relatively acceptable. There are mainly the following requirements: a, there is more than 8 G in the running memory. B, one more USB 3. 0 interface to ensure the transmission of high-definition video, computer USB 3. The color of interface 0 is blue, and the transmission speed is faster.
2. Network selection: The network cable should be connected to the network with an uplink of more than 8M, and live broadcast software should be selected to push the video and audio to the network.
Extended data:
Basic elements of live video:
1, bit rate
The bit rate refers to the number of data bits generated per unit time, with the unit of bps (bits per second),1Mbps =1024 kbps =1048576 bps. Generally, with a fixed resolution, the higher the bit rate, the better the video quality.
(* Please note the difference between bps and B/s, 1B/s=8bps. )
Generally, the bit rate of 720P is about 2~4Mbps, and the bit rate of 1080P is about 4~8Mbps, which is the broadband requirement for users. Watching 720P video requires at least 2M bandwidth.
Watching 1080P video requires at least 4M bandwidth. Under the current domestic network environment, the uplink and downlink rates are not equal. If the anchor wants to use high-definition video, it is necessary to ensure that the uplink bandwidth of the anchor is sufficient.
There are two coding methods, one is called fixed bit rate CBR, that is, coding according to fixed bit rate, and the other is called variable bit rate VBR, that is, coding according to the bit rate that changes according to the actual data size.
Step 2 solve
Resolution refers to the size of the picture. The higher the resolution, the larger the image. Generally speaking, under the condition of constant bit rate, the higher the resolution, the worse the video quality.
There are two kinds of resolutions: 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 resolution standards, such as d 1(720×576), 4c if(704×576), VGA(640×480), SVGA(800×600) and VXGA( 1600×65438).
The resolution is expressed by vertical height plus scanning, such as 720 p( 1280×720, progressive scanning),1080p (1920×1080, progressive scanning) and1080i.
Later, horizontal pixel descriptions were used, such as 2K(2048× 1536 or 2560× 1440 or 2560× 1600) and 4K(4096×2 160 or 3840× 2/kloc).
The resolution below 720P is called standard definition (about 400 lines, such as 480P), 720P is called HD, 1080P/ 1080I is called full HD, and the above is called ultra HD.
3. Frame rate
Frame refers to a single picture in the code stream, and frame rate refers to the number of frames in the code stream per unit time, in fps (frames per second). The sudden change of frame rate is most likely to cause the feeling that the picture is stuck and disconnected, and a stable high frame rate can ensure the smoothness of the video.
Due to the visual pause effect of human eyes, people will think that the pictures with short time difference and small changes are continuous. Usually, when the video frame rate is stable above 30fps, people will feel basically smooth, and 60fps will make people feel very smooth, but above 75fps, people will not notice the improvement of fluency.
The frame rate of movies shown in cinemas is usually 24 frames per second, but people still feel very smooth, because the frames of movies are dynamic and fuzzy, and the human eye will ignore these fuzzy differences, while every frame displayed on the computer is clear, so the requirement for frame rate on the display will be higher than that in cinemas.
4. Packet loss rate.
Packet loss rate refers to the ratio of the number of packets lost in transmission to the total number of packets sent. The greater the packet loss rate, the more serious the picture jam, or even no picture. Generally speaking, when the packet loss rate exceeds 2%, the picture will be obviously dropped.
The method to check the packet loss rate is generally through long ping or tracert (or traceroute), and some tools and software can also be used to detect or simulate packet loss, such as iperf and netperf.
5, time delay (delay)
Generally speaking, it refers to the time spent in the process of data generation and reception, and generally refers to the network transmission delay.
There are many factors that affect network delay, such as packet loss, slow gateway conversion and slow node processing. , which may affect network latency. When there is unstable delay in the network environment, it is easy to cause frame skipping and frame jamming. Usually, the delay of local area network is less than 400 milliseconds, and the delay of wide area network or Internet is less than 3 ~ 5 seconds. ..