Why reolink camera not output H.265 stream when in low resolution?

[user_669525845065812_669525845065812]

I need a low bit rate stream camera with rather clear image, so I choose reolink product with H.265 feature, I baught RLC-820A. 
Firmware version: v3.1.0.956_22041501

I use vlc to check rtsp stream H.264 or H.265(rtsp://admin:pa*sword@192.168.0.157/h265Preview_01_main), I find only resolution 3840*2160 is H.265, other resolution(2560*1440,2304*1296) all be H.264.
But what I need is low bit rate stream, H.265 output only in most high resolution still output too high bit rate.

Why reolink camera not output H.265 stream when in low resolution?

[joseph_1979]

@user_669525845065812_669525845065812 On Reolink cameras H.265 is supported in clear mode as per table on article at https://support.reolink.com/hc/en-us/articles/900000604803-Do-Reolink-Cameras-Support-H-265

[user_654576976203821_654576976203821]

@joseph-chircop_497308027822318 Thank you for sharing this link i got my solution.

[user_723733940359417_723733940359417]

Reolink cameras may not output H.265 stream when in low resolution due to hardware limitations. H.265 encoding requires more processing power than H.264, and lower resolution settings may not provide enough processing power to support H.265 encoding. Additionally, H.265 encoding is typically more beneficial for higher resolution video, as it provides better compression and reduces the file size without sacrificing video quality. Therefore, Reolink cameras may prioritize H.264 encoding for lower resolution settings to ensure smooth video streaming and recording.

[user_724063188017357_724063188017357]

Here are a few potential reasons why a Reolink camera might not output an H.265 stream when in low resolution:

1. Codec Selection Logic: Camera firmware might prioritize H.265 encoding for high-resolution streams to maximize the benefits of compression efficiency. For lower-resolution streams, the camera might default to H.264 encoding if it considers the benefits of H.265 to be less significant due to the reduced data volume.
2. Processing Overhead: While H.265 is efficient for compressing high-resolution video, its compression efficiency might not be as pronounced for lower resolutions. The additional processing required for H.265 encoding might not provide substantial benefits in terms of storage or bandwidth reduction for lower-resolution streams.
3. Hardware Limitations: Some cameras might have hardware limitations that affect their ability to efficiently encode video using H.265, especially at lower resolutions. This could result in decreased performance or even increased file sizes compared to H.264 for low-resolution streams.
4. Firmware and Updates: The camera's firmware plays a significant role in determining how it handles encoding and streaming. Reolink or other camera manufacturers may release firmware updates that modify the encoding behavior based on user feedback or improvements in technology.
5. User Configurations: It's possible that there are configuration settings or options within the camera's interface that influence the choice of encoding. Check the camera's settings to see if there's an option to prioritize H.265 for low-resolution streams.

[cfahome live_694843299213823]

Most Reolink cameras can stream and record in both H.264 and H.265 video compression forms. High Efficiency Video Coding (HEVC), which is another name for H.265, is known for being better at compressing video than H.264. This lets the video quality be better at lower bitrates, which is helpful when you have limited internet or storage space.

But the way you say a Reolink camera doesn't send out an H.265 stream when the resolution is low could be because of the camera's settings or limits. Here are a few possible reasons for this:

1. The software and settings: The firmware and options of the camera could affect how it works. Some cameras are made so that they can only use H.265 at higher resolutions. This is because H.265 works best with high-resolution images. Manufacturers might give H.265 high priority for high-quality streams to save space and bandwidth.

2. Processing Power: H.265 video encoding needs more processing power than H.264 video encoding. The H.265 codec might not be used for lower-resolution streams if the camera's processing power is not enough to handle the decoding process well.

3. It fits together: Some devices or software might handle H.264 better than H.265, especially if they are older or not optimised for newer video codecs. This could change how the camera works when streaming in poor quality.

4.A*signing Resources: Reolink cameras might be made to a*sign resources based on the quality chosen. If the camera sees a smaller resolution setting, it might choose the H.264 codec because it works with more devices and systems.

If you want to know for sure why a certain Reolink camera is acting this way, it's best to check the camera's user instructions or contact Reolink's customer support. They can tell you about the camera's design decisions and what it can't do.