From 66892d00a815c50ec56a7cde455b3048bff8c339 Mon Sep 17 00:00:00 2001
From: Dale Curtis <dalecurtis@chromium.org>
Date: Thu, 13 Mar 2025 23:33:51 +0000
Subject: [PATCH 1/2] Implement orientation support for VideoEncoder.
This implements the algorithm as discussed in the Media WG:
* Orientation is locked-in upon the first call to encode().
* Mismatched orientation will trigger a non-fatal error by throwing
an exception during encode().
* The orientation of the first frame is emitted on the
VideoDecoderConfig attached to EncodedVideoChunkMetadata.
Fixes: https://github.com/w3c/webcodecs/issues/351
---
index.src.html | 28 +++++++++++++++++++++-------
1 file changed, 21 insertions(+), 7 deletions(-)
diff --git a/index.src.html b/index.src.html
index 843d6bd8..7ab7283d 100644
--- a/index.src.html
+++ b/index.src.html
@@ -1402,6 +1402,10 @@
: <dfn attribute for=VideoEncoder>[[dequeue event scheduled]]</dfn>
:: A boolean indicating whether a {{VideoEncoder/dequeue}} event is already
scheduled to fire. Used to avoid event spam.
+: <dfn attribute for=VideoEncoder>[[active orientation]]</dfn>
+:: An integer and boolean pair indicating the {{VideoFrame/[[flip]]}} and
+ {{VideoFrame/[[rotation]]}} of the first {{VideoFrame}} given to
+ {{VideoEncoder/encode()}} after {{VideoEncoder/configure()}}.
Constructors {#videoencoder-constructors}
-----------------------------------------
@@ -1461,8 +1465,9 @@
2. If {{VideoEncoder/[[state]]}} is `"closed"`, throw an
{{InvalidStateError}}.
3. Set {{VideoEncoder/[[state]]}} to `"configured"`.
- 4. [=Queue a control message=] to configure the encoder using |config|.
- 5. [=Process the control message queue=].
+ 4. Set {{VideoEncoder/[[active orientation]]}} to `null`.
+ 5. [=Queue a control message=] to configure the encoder using |config|.
+ 6. [=Process the control message queue=].
[=Running a control message=] to configure the encoder means performing
these steps:
@@ -1491,11 +1496,16 @@
is `true`, throw a {{TypeError}}.
2. If {{VideoEncoder/[[state]]}} is not `"configured"`, throw an
{{InvalidStateError}}.
- 3. Let |frameClone| hold the result of running the [=Clone VideoFrame=]
+ 3. If {{VideoEncoder/[[active orientation]]}} is not `null` and does not match
+ |frame|'s {{VideoFrame/[[rotation]]}} and {{VideoFrame/[[flip]]}} throw a
+ {{DataError}}.
+ 4. If {{VideoEncoder/[[active orientation]]}} is `null`, assign |frame|'s
+ {{VideoFrame/[[rotation]]}} and {{VideoFrame/[[flip]]}} to it.
+ 5. Let |frameClone| hold the result of running the [=Clone VideoFrame=]
algorithm with |frame|.
- 4. Increment {{VideoEncoder/[[encodeQueueSize]]}}.
- 5. [=Queue a control message=] to encode |frameClone|.
- 6. [=Process the control message queue=].
+ 6. Increment {{VideoEncoder/[[encodeQueueSize]]}}.
+ 7. [=Queue a control message=] to encode |frameClone|.
+ 8. [=Process the control message queue=].
[=Running a control message=] to encode the frame means performing these
steps:
@@ -1646,7 +1656,11 @@
`outputConfig.displayAspectWidth`.
5. Assign `encoderConfig.displayHeight` to
`outputConfig.displayAspectHeight`.
- 6. Assign the remaining keys of `outputConfig` as determined by
+ 6. Assign {{VideoFrame/[[rotation]]}} from the {{VideoFrame}}
+ associated with |output| to `outputConfig.rotation`.
+ 7. Assign {{VideoFrame/[[flip]]}} from the {{VideoFrame}}
+ associated with |output| to `outputConfig.flip`.
+ 8. Assign the remaining keys of `outputConfig` as determined by
{{VideoEncoder/[[codec implementation]]}}. The User Agent
<em class="rfc2119">MUST</em> ensure that the configuration is
completely described such that |outputConfig| could be used to
From e3bd4010d70e15564424374012a95c6cfd9c68eb Mon Sep 17 00:00:00 2001
From: Dale Curtis <dalecurtis@chromium.org>
Date: Fri, 14 Mar 2025 12:01:56 -0700
Subject: [PATCH 2/2] Accept suggestion to clarify active orientation setting.
Co-authored-by: Paul Adenot <paul@paul.cx>
---
index.src.html | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/index.src.html b/index.src.html
index 7ab7283d..e571e6a6 100644
--- a/index.src.html
+++ b/index.src.html
@@ -1499,8 +1499,8 @@
3. If {{VideoEncoder/[[active orientation]]}} is not `null` and does not match
|frame|'s {{VideoFrame/[[rotation]]}} and {{VideoFrame/[[flip]]}} throw a
{{DataError}}.
- 4. If {{VideoEncoder/[[active orientation]]}} is `null`, assign |frame|'s
- {{VideoFrame/[[rotation]]}} and {{VideoFrame/[[flip]]}} to it.
+ 4. If {{VideoEncoder/[[active orientation]]}} is `null`, set it to |frame|'s
+ {{VideoFrame/[[rotation]]}} and {{VideoFrame/[[flip]]}}.
5. Let |frameClone| hold the result of running the [=Clone VideoFrame=]
algorithm with |frame|.
6. Increment {{VideoEncoder/[[encodeQueueSize]]}}.