W3C home > Mailing lists > Public > public-webrtc-logs@w3.org > September 2017

Re: [webrtc-pc] Deciding on resolutions with scaleResolutionDownBy

From: jan-ivar via GitHub <sysbot+gh@w3.org>
Date: Wed, 13 Sep 2017 00:01:34 +0000
To: public-webrtc-logs@w3.org
Message-ID: <issue_comment.created-329018223-1505260885-sysbot+gh@w3.org>
What about the third case?
> * The encoder doesn't handle scaling to certain resolutions 
>   * webrtc.org requires that all layers have identical aspect ratio, see [1]

Rounding to the nearest integer can create unintended aspect changes. Consider:

```js
await sender.setParameters({encodings: [
  { rid: "high" },                             // 320x240
  { rid: "medium", scaleResolutionDownBy: 2 }, // 160x120 (320*120 - 160*240 = 0)
  { rid: "low", scaleResolutionDownBy: 3 },    // 107x80  (320*80 - 107*240 = -80)
]});
```

-- 
GitHub Notification of comment by jan-ivar
Please view or discuss this issue at https://github.com/w3c/webrtc-pc/issues/1564#issuecomment-329018223 using your GitHub account
Received on Wednesday, 13 September 2017 00:01:28 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 4 June 2019 15:32:45 UTC