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webp-container-spec: consistently quote FourCCs
from the AUTH48 portion of the RFC review process Change-Id: I3aad4b32c95517735e98ffa0120228ee24be6a4d
This commit is contained in:
James Zern
parent
49918af32b
commit
f6499943c4
@ -188,10 +188,10 @@ Simple WebP (lossy) file format:
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| WebP file header (12 bytes) |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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: VP8 chunk :
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: 'VP8 ' Chunk :
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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VP8 chunk:
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'VP8 ' Chunk:
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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@ -235,10 +235,10 @@ Simple WebP (lossless) file format:
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| WebP file header (12 bytes) |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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: VP8L chunk :
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: 'VP8L' Chunk :
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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VP8L chunk:
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'VP8L' Chunk:
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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@ -266,17 +266,17 @@ Extended File Format
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An extended format file consists of:
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* A 'VP8X' chunk with information about features used in the file.
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* A 'VP8X' Chunk with information about features used in the file.
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* An optional 'ICCP' chunk with color profile.
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* An optional 'ICCP' Chunk with a color profile.
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* An optional 'ANIM' chunk with animation control data.
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* An optional 'ANIM' Chunk with animation control data.
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* Image data.
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* An optional 'EXIF' chunk with Exif metadata.
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* An optional 'EXIF' Chunk with Exif metadata.
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* An optional 'XMP ' chunk with XMP metadata.
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* An optional 'XMP ' Chunk with XMP metadata.
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* An optional list of [unknown chunks](#unknown-chunks).
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@ -295,7 +295,7 @@ appears in the wrong place, the file is invalid, but readers MAY parse the
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file, ignoring the chunks that are out of order.
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**Rationale:** Setting the order of chunks should allow quicker file
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parsing. For example, if an 'ALPH' chunk does not appear in its required
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parsing. For example, if an 'ALPH' Chunk does not appear in its required
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position, a decoder can choose to stop searching for it. The rule of
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ignoring late chunks should make programs that need to do a full search
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give the same results as the ones stopping early.
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@ -343,7 +343,7 @@ XMP metadata (X): 1 bit
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Animation (A): 1 bit
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: Set if this is an animated image. Data in 'ANIM' and 'ANMF' chunks should be
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: Set if this is an animated image. Data in 'ANIM' and 'ANMF' Chunks should be
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used to control the animation.
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Reserved (R): 1 bit
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@ -372,9 +372,9 @@ Future specifications may add more fields. Unknown fields MUST be ignored.
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#### Animation
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An animation is controlled by ANIM and ANMF chunks.
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An animation is controlled by 'ANIM' and 'ANMF' Chunks.
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ANIM Chunk:
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'ANIM' Chunk:
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{:#anim_chunk}
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For an animated image, this chunk contains the _global parameters_ of the
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@ -414,11 +414,11 @@ Loop Count: 16 bits (_uint16_)
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: The number of times to loop the animation. If it is `0`, this means
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infinitely.
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This chunk MUST appear if the _Animation_ flag in the VP8X chunk is set.
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This chunk MUST appear if the _Animation_ flag in the 'VP8X' Chunk is set.
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If the _Animation_ flag is not set and this chunk is present, it MUST be
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ignored.
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ANMF chunk:
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'ANMF' Chunk:
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For animated images, this chunk contains information about a _single_ frame.
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If the _Animation flag_ is not set, then this chunk SHOULD NOT be present.
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@ -619,10 +619,10 @@ Alpha bitstream: _Chunk Size_ - `1` bytes
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: Encoded alpha bitstream.
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This optional chunk contains encoded alpha data for this frame. A frame
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containing a 'VP8L' chunk SHOULD NOT contain this chunk.
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containing a 'VP8L' Chunk SHOULD NOT contain this chunk.
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**Rationale**: The transparency information is already part of the 'VP8L'
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chunk.
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Chunk.
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The alpha channel data is stored as uncompressed raw data (when the
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compression method is '0') or compressed using the lossless format
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@ -685,14 +685,14 @@ If this chunk is not present, sRGB SHOULD be assumed.
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#### Metadata
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Metadata can be stored in 'EXIF' or 'XMP ' chunks.
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Metadata can be stored in 'EXIF' or 'XMP ' Chunks.
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There SHOULD be at most one chunk of each type ('EXIF' and 'XMP '). If there
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are more such chunks, readers MAY ignore all except the first one.
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The chunks are defined as follows:
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EXIF chunk:
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'EXIF' Chunk:
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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@ -707,7 +707,7 @@ Exif Metadata: _Chunk Size_ bytes
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: Image metadata in Exif format.
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XMP chunk:
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'XMP ' Chunk:
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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