| Term | Definition | Impact on Quality | |------|------------|-------------------| | | Number of horizontal × vertical pixels (e.g., 1920 × 1080). | Higher resolution → more detail, larger file size. | | Aspect Ratio (AR) | Ratio of width to height (e.g., 16:9, 4:3). | Must be preserved unless a purposeful crop/pillar‑box. | | Pixel Aspect Ratio (PAR) | Shape of a single pixel (square vs. rectangular). | Important when converting from legacy formats (e.g., 720×480 NTSC). | | Scaling Factor | Ratio of target dimension to source dimension (e.g., 0.5 for down‑scale by half). | Determines how many new samples are interpolated or discarded. | | Interpolation | Algorithm that estimates pixel values for the new resolution. | The choice of interpolation directly determines sharpness, ringing, and aliasing. | | Upscaling vs. Downscaling | Upscaling: increase pixel count; Downscaling: decrease pixel count. | Upscaling cannot create new detail; downscaling discards information. | | Bit‑depth & Color Space | Number of bits per channel (8‑bit, 10‑bit) and color model (YUV, RGB). | Higher bit‑depth mitigates banding when scaling, especially in gradients. | | Chroma Subsampling | Ratio of luma to chroma samples (e.g., 4:2:0, 4:4:4). | Downsampling can cause color bleeding; keep 4:4:4 when high‑quality scaling is needed. |
| Use‑Case | Typical Target Resolutions | Reason for Scaling | |----------|----------------------------|--------------------| | | 480 p, 720 p, 1080 p, 4K | Adaptive bitrate streaming (HLS/DASH) needs several renditions. | | Social media | 720 p (Instagram), 1080 p (YouTube), 4K (TikTok) | Platform‑specific limits and optimal upload sizes. | | Broadcast & OTT | 720 p, 1080 p, 4K, 8K | Conform to carrier standards (e.g., ATSC, DVB). | | Device‑specific playback | 360 p (smartwatches), 1080 p (smart TVs) | Match display native resolution to avoid unnecessary scaling at playback. | | Archival & Mastering | 4K‑UHD or higher | Preserve a high‑resolution master, then create lower‑resolution derivatives. | | Performance / Bandwidth constraints | 240 p–480 p (low‑bandwidth networks) | Reduce file size, improve buffering. | video syaliong
"Why does my video keep stalling?"
| Tool | Core Technology | Typical Upscaling Ratio | Pros | Cons | |------|-----------------|------------------------|------|------| | | Deep CNN trained on 2‑X, 4‑X data | 2‑X, 4‑X, 6‑X | Excellent edge preservation, de‑noise | Proprietary, pricey | | Real‑ESRGAN (Open‑Source) | Residual-in-Residual Dense Block (RRDB) | 2‑X, 4‑X | Free, customizable | Needs GPU, may produce “soft” textures | | DAIN (Depth‑Aware Frame Interpolation) | Optical‑flow + AI for temporal up‑sampling | Temporal (frame‑rate) up‑scaling | Smooth slow‑motion | Heavy memory usage | | Google’s RIFE | Re‑current Interpolation Flow Estimation | Frame‑rate up‑scale | Fast, decent quality | Limited to modest resolution increases | | Term | Definition | Impact on Quality