With the popularity of distance learning, video conferencing, webinars and online training, recording and broadcasting servers have become an indispensable technical tool for education, enterprises and media industries. As the core of the recording and broadcasting system, the recording and broadcasting server assumes the key responsibilities of video acquisition, encoding, storage and distribution. In the actual deployment process, the three indicators of resolution, bit rate and frame rate have a decisive impact on the recording and broadcasting quality, storage cost and network bandwidth occupancy.
1. Resolution support comparison
Resolution determines the clarity of the video image. In the recording and broadcasting scenario, the common resolutions are mainly the following:
Resolution 480p: pixel size 720×480, video ratio 16:9, suitable for low bit rate live broadcast, mobile terminal priority
Resolution 720p: pixel size 1280×720, video ratio 16:9, suitable for mainstream high-definition video teaching
Resolution 1080p: pixel size 1920×1080, video ratio 16:9, suitable for high-quality live broadcast and recording
Resolution 2K: pixel size 2560×1440, video ratio 16:9, suitable for high-definition conference or large-screen display
Resolution 4K: pixel size 3840×2160, video ratio 16:9, suitable for professional teaching, broadcasting and television level
Most of the mainstream recording and broadcasting servers on the market currently support recording from 480p to 1080p, among which mid-to-high-end products can support 2K or even 4K resolution. It should be noted that the higher the resolution, the greater the encoding processing capacity and storage pressure, so the image quality and cost should be weighed when choosing.
2. Bit rate range comparison
Bit rate is an important indicator to measure the size of video data stream, and the unit is generally kbps or Mbps. Bitrate directly affects video quality and occupied bandwidth:
Resolution 480: recommended bitrate range p800kbps - 1.5Mbps, smooth picture quality, slightly mosaic
Resolution 720p: recommended bitrate range 1.5Mbps - 3Mbps, clear picture quality, moderate picture quality
Resolution 1080: recommended bitrate range p3Mbps - 6Mbps, high-definition picture quality, good detail restoration
Resolution 2K: recommended bitrate range 6Mbps - 12Mbps, extremely clear picture quality, professional picture
Resolution 4K: recommended bitrate range 12Mbps - 25Mbps, extremely high-definition picture quality
Different brands of recording and broadcasting servers have slightly different bitrate settings. Some devices use constant bitrate (CBR), which is suitable for stable network scenarios; others use variable bitrate (VBR), which can dynamically and adaptively adjust the data volume according to the picture to improve the quality and stability of the video stream.
3. Frame rate selection and comparison
Frame rate is the number of images displayed per second in a video, measured in FPS. Common frame rates include 15FPS, 24FPS, 30FPS, 60FPS, etc.
15FPS takes up less bandwidth, saves resources, slightly jerky images, not smooth audio-dominated teaching (such as voice)
24FPS is a movie-level standard, visually natural, not suitable for high-speed dynamic image explanation courses
30FPS has a high degree of fluency, and mainstream standard resources are used in a medium-general purpose lecture, conference, and course
60FPS is extremely smooth, with clear motion and large resource usage. Sports, action demonstrations, and practical courses
The recording and broadcasting server is usually set to 30FPS by default, which is a comfortable frame rate for most people to watch. Under the premise of sufficient bandwidth and strong processing power, 60FPS can provide a more delicate visual experience, but it is not recommended for all occasions.
4. Differences in hardware encoding and compatibility
The recording and broadcasting server is also limited by the encoding chip and system architecture used in terms of supported resolution and frame rate. For example:
CPU software encoding: supports a wide range of formats but limited performance, suitable for light-load applications;
GPU hardware acceleration (such as NVIDIA NVENC): efficient processing of high-resolution multi-channel video, but high cost;
Professional encoding cards (such as Magewell, AJA): suitable for broadcasting-level recording, compatible with 4K and even 8K.
Some low-end devices claim to support 4K, but the actual frame rate is only 15FPS, or only support playback but not real-time recording. Users need to pay special attention to product technical specifications when purchasing.
The resolution, bit rate and frame rate of the recording and broadcasting server are key parameters that affect video quality and system efficiency. Understanding and correctly matching the three can achieve the best video recording and distribution experience in different scenarios. When selecting, users should combine their own scenarios, budgets, viewing terminals and network conditions to reasonably formulate recording and broadcasting configuration plans to ensure user experience and improve system performance.
When selecting recording and broadcasting equipment, avoid blindly stacking parameters, but should take "applicability first, stability first" as the basic principle to achieve long-term and efficient operation of the recording and broadcasting system.
