Add per-frame QP support to AVC

This value is used by VideoEncoder.encode() if VideoEncoder is configured with "quantizer" bitrate mode. Followup for: w3c#270

Author: aboba

avc_codec_registration.src.html

@@ -17,7 +17,8 @@
  {{EncodedVideoChunk/[[internal data]]}} bytes, (3) the
  {{VideoDecoderConfig/description|VideoDecoderConfig.description}} bytes,
  (4) the values of {{EncodedVideoChunk}} {{EncodedVideoChunk/[[type]]}},
- and (5) the codec-specific extensions to {{VideoEncoderConfig}}
+ (5) the codec-specific extensions to {{VideoEncoderConfig}}, and
+ (6) the codec-specific extensions to {{VideoEncoderEncodeOptions}}.
 
  The registration is not intended to include any information on whether a
  codec format is encumbered by intellectual property claims. Implementers and
@@ -187,6 +188,42 @@
  player generally has random access to the media data.
 </dl>
 
+VideoEncoderEncodeOptions extensions {#videoencoderencodeoptions-extensions}
+==============================================================
+
+<pre class='idl'>
+<xmp>
+partial dictionary VideoEncoderEncodeOptions {
+ VideoEncoderEncodeOptionsForAvc avc;
+};
+</xmp>
+</pre>
+
+<dl>
+ <dt><dfn dict-member for=VideoEncoderEncodeOptions>avc</dfn></dt>
+ <dd>
+ Contains codec specific encode options for the [[ITU-T-REC-H.264]] codec.
+ </dd>
+</dl>
+
+VideoEncoderEncodeOptionsForAv1 {#av1-encode-options}
+--------------------------------------
+<pre class='idl'>
+<xmp>
+dictionary VideoEncoderEncodeOptionsForAvc {
+ unsigned short? quantizer;
+};
+</xmp>
+</pre>
+
+<dl>
+ <dt><dfn dict-member for=VideoEncoderEncodeOptionsForAvc>quantizer</dfn></dt>
+ <dd>
+ Sets per-frame quantizer value.
+ In [[ITU-T-REC-H.264]] the quantizer threshold can be varied from 0 to 51
+ </dd>
+</dl>
+
 Privacy Considerations {#privacy-considerations}
 ==========================================================================