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Merge pull request #149 from WICG/establish_codec_registry
Establish codec registry and AVC registration.
2 parents 57e2560 + 49baae7 commit cf0784b

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‎.gitignore

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out/
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index.html
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avc_codec_registration.html
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codec_registry.html
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deploy_key
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deploy_key.pub
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index.html
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out/
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‎Makefile

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SHELL=/bin/bash
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local: index.src.html
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local: local-index local-codec-registry local-avc-codec-registration
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local-index: index.src.html
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bikeshed --die-on=warning spec index.src.html index.html
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index.html: index.src.html
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local-codec-registry: codec_registry.src.html
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bikeshed --die-on=warning spec codec_registry.src.html codec_registry.html
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local-avc-codec-registration: avc_codec_registration.src.html
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bikeshed --die-on=warning spec avc_codec_registration.src.html avc_codec_registration.html
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remote-index: index.src.html
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@ (HTTP_STATUS=$$(curl https://api.csswg.org/bikeshed/ \
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--output index.html \
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--write-out "%{http_code}" \
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exit 22 \
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);
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remote: index.html
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remote-codec-registry: codec_registry.src.html
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@ (HTTP_STATUS=$$(curl https://api.csswg.org/bikeshed/ \
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--output codec_registry.html \
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--write-out "%{http_code}" \
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--header "Accept: text/plain, text/html" \
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-F die-on=warning \
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-F file=@codec_registry.src.html) && \
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[[ "$$HTTP_STATUS" -eq "200" ]]) || ( \
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echo ""; cat codec_registry.html; echo ""; \
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rm -f codec_registry.html; \
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exit 22 \
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);
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remote-avc-codec-registration: avc_codec_registration.src.html
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@ (HTTP_STATUS=$$(curl https://api.csswg.org/bikeshed/ \
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--output avc_codec_registration.html \
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--write-out "%{http_code}" \
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--header "Accept: text/plain, text/html" \
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-F die-on=warning \
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-F file=@avc_codec_registration.src.html) && \
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[[ "$$HTTP_STATUS" -eq "200" ]]) || ( \
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echo ""; cat avc_codec_registration.html; echo ""; \
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rm -f avc_codec_registration.html; \
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exit 22 \
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);
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remote: remote-index remote-codec-registry remote-avc-codec-registration
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ci: index.src.html
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ci: index.src.html codec_registry.src.html avc_codec_registration.src.html
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mkdir -p out
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make remote
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mv index.html out/index.html
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clean:
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rm index.html
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rm -rf out
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mv codec_registry.html out/codec_registry.html
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mv avc_codec_registration.html out/avc_codec_registration.html

‎avc_codec_registration.src.html

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<pre class='metadata'>
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Title: AVC (H.264) WebCodecs Registration
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Repository: wicg/web-codecs
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Status: CG-DRAFT
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Shortname: webcodecs-avc-codec-registration
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Level: none
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Group: wicg
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ED: none
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Editor: Chris Cunningham, w3cid 114832, Google Inc. https://google.com/
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Editor: Paul Adenot, w3cid 62410, Mozilla https://www.mozilla.org/
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Editor: Bernard Aboba, w3cid 65611, Microsoft Corporation https://www.microsoft.com/
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Boilerplate: omit conformance
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Abstract: This registration is entered into the [[webcodecs-codec-registry]].
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It describes, for AVC (H.264), the (1) fully qualified codec strings, (2)
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the {{VideoDecoderConfig.description}} bytes, and (3) the
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codec-specific extensions to the {{VideoEncoderConfig}}.
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The registration is not intended to include any information on whether a
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codec format is encumbered by intellectual property claims. Implementers and
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authors are advised to seek appropriate legal counsel in this matter if they
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intend to implement or use a specific codec format. Implementers of
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WebCodecs are not required to support the AVC / H.264 codec.
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This registration is non-normative.
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Markup Shorthands:css no, markdown yes, dfn yes
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!Participate: <a href="https://github.com/wicg/web-codecs">Git Repository.</a>
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!Participate: <a href="https://github.com/wicg/web-codecs/issues/new">File an issue.</a>
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!Version History: <a href="https://github.com/wicg/web-codecs/commits">https://github.com/wicg/web-codecs/commits</a>
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</pre>
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<pre class='anchors'>
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spec: webcodecs; urlPrefix: https://wicg.github.io/web-codecs/#
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type: attribute
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text: VideoDecoderConfig.description; url: dom-videodecoderconfig-description
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type: interface
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text: EncodedVideoChunk; url: encodedvideochunk
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text: VideoEncoder; url: videoencoder
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type: dictionary
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text: VideoEncoderConfig; url: dictdef-videoencoderconfig
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text: VideoDecoderConfig; url: dictdef-videodecoderconfig
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</pre>
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<pre class='biblio'>
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{
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"WEBCODECS": {
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"href": "https://wicg.github.io/web-codecs/",
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"title": "WebCodecs",
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"publisher": "WICG"
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},
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"WEBCODECS-CODEC-REGISTRY": {
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"href": "https://wicg.github.io/web-codecs/codec_registry.html",
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"title": "WebCodecs Codec Registry",
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"publisher": "WICG"
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},
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"ITU-T-REC-H.264": {
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"href": "https://www.itu.int/rec/T-REC-H.264",
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"title": "H.264 : Advanced video coding for generic audiovisual services",
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"publisher": "ITU",
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"date": "June 2019"
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}
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}
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</pre>
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Fully qualified codec strings {#fully-qualified-codec-strings}
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==============================================================
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The codec string must begin with the prefix "avc1.", and contain a suffix of 6
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characters as described in Section 3.4 of [[rfc6381]].
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NOTE: The common "avc3." prefix is intentionally not included. This prefix does
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not signal a material difference to decoder inputs, so it is omitted for
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simplification. For the purposes of this registration, authors should simply
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map "avc3." to "avc1.".
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VideoDecoderConfig description {#videodecoderconfig-description}
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================================================================
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A {{VideoDecoderConfig.description}} may or may not be required by the
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AVC codec depending on the bitstream format of the AVC content to be decoded.
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If the {{VideoDecoderConfig.description}} includes an
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`AVCDecoderConfigurationRecord`, as defined by [[iso14496-15]], section
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5.3.3.1, it will be assumed that the bitstream is in "avc" format.
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NOTE: This format is commonly used in .MP4 files, where the player generally
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has random access to the media data.
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If the {{VideoDecoderConfig.description}} is not provided, it will be
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assumed that the bitstream is in “annexb” format.
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NOTE: "annexb" format is described in greater detail by [[ITU-T-REC-H.264]],
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Annex B. This format is commonly used in live-streaming applications, where
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including the SPS and PPS data periodically allows users to easily start
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from the middle of the stream.
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VideoEncoderConfig extensions {#videoencoderconfig-extensions}
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==============================================================
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<pre class='idl'>
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<xmp>
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partial dictionary VideoEncoderConfig {
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AvcEncoderConfig avc;
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};
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</xmp>
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</pre>
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<dl>
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<dt><dfn dict-member for=VideoEncoderConfig>avc</dfn></dt>
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<dd>
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Contains codec specific configuration options for the AVC (H.264) codec.
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</dd>
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</dl>
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AvcEncoderConfig {#avc-encoder-config}
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--------------------------------------
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<pre class='idl'>
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<xmp>
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dictionary AvcEncoderConfig {
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AvcBitstreamFormat format = "avc";
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};
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</xmp>
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</pre>
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<dl>
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<dt><dfn dict-member for=AvcEncoderConfig>format</dfn></dt>
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<dd>
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Configures the format of output {{EncodedVideoChunk}}s. See
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{{AvcBitstreamFormat}}.
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</dd>
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</dl>
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AvcBitstreamFormat {#avc-bitstream-format}
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------------------------------------------
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<pre class='idl'>
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<xmp>
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enum AvcBitstreamFormat {
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"annexb",
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"avc",
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};
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</xmp>
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</pre>
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The {{AvcBitstreamFormat}} determines the location of AVC Sequence Parameter
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Set (SPS) and Picture Parameter Set (PPS) data, and mechanisms for packaging
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the bitstream.
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SPS and PPS are described in greater detail in sections G.3.41 and G.3.55 of
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[[ITU-T-REC-H.264]].
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<dl>
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<dt><dfn enum-value for=AvcBitstreamFormat>annexb</dfn></dt>
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<dd>
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SPS and PPS data are included periodically throughout the bitstream.
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NOTE: This format is described in greater detail by [[ITU-T-REC-H.264]],
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Annex B. This format is commonly used in live-streaming applications,
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where including the SPS and PPS data periodically allows users to easily
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start from the middle of the stream.
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</dd>
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<dt><dfn enum-value for=AvcBitstreamFormat>avc</dfn></dt>
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<dd>
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SPS and PPS data are not included in the bitstream and are instead emitted
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via the {{VideoEncoder}} [[output callback]] as the
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{{VideoDecoderConfig.description}} of the
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{{VideoDecoderConfig}}.
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<var ignore=''>output_config</var>.
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NOTE: This format is described in greater detail by [[iso14496-15]],
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section 5.3.3.1. This format is commonly used in .MP4 files, where the
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player generally has random access to the media data.
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</dl>

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