Resolution: Encoding up to 2160P
What’s the highest resolution supported by 4K Encoder ON-DMI-52B?
Normally, for encoding, the HDMI encoder supports a maximum resolution of 3840x2160P.
Bitrate mode: CBR/VBR
Does the HDMI encoder support different bitrate control modes?
Yes, the HDMI encoder supports both CBR (Constant Bitrate) and VBR (Variable Bitrate) modes.
Key Features:
1. CBR (Constant Bitrate):
- Maintains a consistent bitrate throughout the video stream.
- Ideal for environments with limited bandwidth or for ensuring stable network transmission.
- Ensures predictable network performance and reduces the risk of buffering issues.
2. VBR (Variable Bitrate):
- Adjusts the bitrate dynamically based on the complexity of the video content.
- Delivers better video quality for the same file size compared to CBR.
- Suitable for scenarios where video quality is prioritized and bandwidth is more flexible.
Applications:
- Use CBR for live streaming over constrained or inconsistent network conditions to minimize interruptions.
- Use VBR for recording or streaming scenarios where quality is more critical than a stable bitrate.
By supporting both modes, the streaming encoder provides flexibility to meet diverse requirements for video quality and network performance.
Framerate: Encoding Up to 60FPS
NOTES: It's required to switch the System Mode from Setting->System->
System Setting. Learn more about
System Setting of Encoder.
How can we measure the actual frames per second?
To test the real frames per second (FPS) of an RTSP stream using PotPlayer, you can use the built-in video playback statistics feature in the software. PotPlayer provides an option to display video playback information, including the current frames per second (FPS) rate. Here's how you can test the real FPS of an RTSP stream with PotPlayer:
- Install PotPlayer: If you haven't already done so, download and install PotPlayer on your computer. PotPlayer is a multimedia player that supports various streaming protocols, including RTSP.
- Open PotPlayer and Play the RTSP Stream: Launch PotPlayer and select the option to open a network stream or URL. Enter the RTSP stream's URL or network location to start playing the stream in PotPlayer.
- Display Video Playback Statistics: While the RTSP stream is playing, right-click on the PotPlayer window to access the context menu. From the context menu, select "Playback Information" or "Statistics" (the specific label may vary based on the PotPlayer version).
- View Frames Per Second (FPS): The video playback statistics window will display information about the video being played, including the real-time frames per second (FPS) rate. Monitor the FPS value to observe the actual frame rate of the RTSP stream.
By following these steps, you can use PotPlayer to test the real frames per second (FPS) of an RTSP stream. PotPlayer's video playback statistics feature allows you to monitor the real-time FPS rate, providing insight into the smoothness and performance of the video stream playback.
Gop(Key Interval):
Why should we lower Key Interval(GOP)?
Lowering the Key interval (GOP) can help improve image quality by reducing the amount of compression applied to each frame. This can result in a higher overall image quality, especially for fast-moving or complex scenes. However, this may also increase the file size and processing requirements, so it's important to balance the trade-offs based on the specific needs of the project.
Can we set GOP(Key Interval) to 0–1 to achieve lower latency?
No, it is not possible to set the GOP (Key Interval) to 0–1 on our encoders or encoder/decoder devices. This limitation is intentional and serves to ensure the stability and reliability of the video stream. For all of our devices, the GOP is set to a minimum of 5, and the firmware does not allow adjustments below this threshold.
Why can't GOP(Key Interval) be set lower?
- Stream Stability: Allowing unrestricted GOP values could lead to stream instability, such as fluctuating video quality and unreliable transmission.
- Bitrate Management: Setting a very low GOP could result in inefficient bitrate usage, negatively affecting overall performance.
Why should we balance GOP and Framerate for optimal streaming?
It is critical to balance the GOP and frame rate settings dynamically:
- Keyframe Interval (GOP): Minimum of 5 is required to maintain efficient compression and reliable streaming.
- Frame Rate: Adjust according to application needs (e.g., 30 fps or 25 fps for real-time interaction).
Improper adjustment of these factors may lead to: Increased latency and Degraded image quality.
How to set up Frame Rate and Key Interval (GOP) for Lower Latency?
To achieve lower latency in your HDMI encoder, you can configure the following parameters:
1. Frame Rate Settings
- Recommended Setting: Lower the frame rate to match the application’s requirements without compromising video quality.
- For instance, if real-time interaction is the priority, a frame rate of 30 fps or 25 fps is commonly used.
- Lowering the frame rate reduces processing and transmission delays.
2. Key Interval (GOP) Settings
- The key interval (also known as GOP – Group of Pictures) determines how often a keyframe is inserted in the video stream.
- Recommended Setting: Use a smaller key interval for lower latency, such as 1–2 seconds.
- Example: For a 30 fps video, set the key interval to 30–60 frames.
- Smaller intervals ensure that keyframes are more frequent, making it easier for the decoder to start rendering frames with minimal delay.
3. Encoder Bitrate Mode
- Choose CBR (Constant Bitrate) to stabilize the data transmission, which can help in reducing latency, especially on networks with limited bandwidth.
4. Resolution Adjustment
- Lowering the resolution (e.g., from 1080p to 720p) can also contribute to faster encoding, transmission, and decoding times.
Other Considerations:
- Ensure the network has minimal jitter and stable bandwidth to support low-latency streaming.
- If the video is being transmitted over the internet, use protocols designed for low latency, such as SRT (Secure Reliable Transport) or RTMP Low Latency.
By combining these adjustments, you can significantly reduce latency while maintaining an acceptable balance of video quality and performance.
Bitrate: 500bit/s Initially