Pros:
1. Reduced File Size: Online compression usually reduces the file size significantly. By downscaling the video to 1080p before compression, you can further decrease the file size, making it easier to upload, share, and stream. This can be particularly beneficial if you have limited bandwidth or storage space.
2. Faster Processing and Transfer: Smaller file sizes mean faster processing times and data transfers. Downscaling to 1080p can help in reducing the time required for encoding, uploading, and downloading the video.
3. Compatibility with Devices: Many devices, including older TVs and streaming platforms, may not support 4K resolution. Downscaling to 1080p ensures compatibility with a broader range of devices, allowing more people to access your video content.
Cons:
1. Loss of Detail: Downscaling from 4K to 1080p involves reducing the resolution, which results in a loss of detail. Some fine details and sharpness may be compromised during the downscaling process, especially if the original 4K footage was very high-quality.
2. Visible Artifacts: Depending on the downscaling algorithm used, you may notice some visual artifacts or distortions in the downscaled video. These artifacts can include pixelation, blurring, and aliasing (jagged edges).
3. Reduced Visual Quality: While 1080p is still a high-resolution format, it offers less visual clarity compared to 4K. If the original 4K footage is of exceptional quality, downscaling to 1080p may result in a noticeable decrease in visual fidelity.
Ultimately, the decision of whether to downscale 4K to 1080p after online compression depends on your priorities. If file size reduction, compatibility, and faster processing are your main concerns, downscaling can be a viable option. However, if preserving the highest visual quality is crucial, it's recommended to keep the 4K resolution.