| GreenIT | V2 | V3 | V4 |
|---|---|---|---|
| 92 | 115 | 114 |
| Life cycle | Tiers | Responsible |
|---|---|---|
| 5. Use | User/Device | User |
| Priority | Implementation difficulty | Ecological impact |
|---|---|---|
| 3 | 2 | 3 |
| Saved resources |
|---|
| Processor / Network |
Provide several formats (size, frame rate, audio compression, etc.) depending on the video watching context (desktop, Wi-Fi tablet, EDGE smartphone).
Video optimization should be done out of the website, ideally during post-production. If not possible, use services like YouTube or Vimeo since they offer several optimized formats (SD, HD, etc.) by default.
A 15-second user guide shot in 1,680 x 1,050 resolution weighs:
- 49 MB when not optimized;
- 3 MB when optimized for a resolution equal to or greater than 1,024 x 720 in MPEG 4/H.264/AAC;
- 1.2 MB when optimized for a resolution equal to or greater than 480 x 320 in MPEG 4/H.264/AAC.
It can be estimated that there is at least a 50% size gain (and probably savings during decoding, as the encoding format takes targeted hardware into consideration) between "desktop" and "mobile" video versions.
Most cases should be covered with 3 different sizes x 3 different encodings, i.e., 9 versions of the same video. It is possible to serve the right file with simple rules such as screen resolution with a responsive design logic.
| The number of ... | is equal to or less than |
|---|---|
| videos with a definition of 1080p or higher displayed on the website when the device is a smartphone | 0 |