gecko-dev/image/DecoderFactory.h
Andrew Osmond 874ce61a83 Bug 1901078 - Implement promise based anonymous image decoder. r=tnikkel
This bypasses any caching used on the display pipeline and is
intended to be used by layers that want asynchronous decoding
that fits well into the MozPromise style.

This also fixes an issue with the frame count metadata decoder in the
GIF decoder. The code only began being used with this patch, and the WPT
exposed an overflow bug caused by not clearing nsGIFDecoder2::mColormap
and nsGIFDecoder2::mColormapSize.

Differential Revision: https://phabricator.services.mozilla.com/D212833
2024-07-24 03:16:16 +00:00

205 lines
9.1 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_image_DecoderFactory_h
#define mozilla_image_DecoderFactory_h
#include "DecoderFlags.h"
#include "mozilla/Attributes.h"
#include "mozilla/Maybe.h"
#include "mozilla/NotNull.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/image/ImageUtils.h"
#include "nsCOMPtr.h"
#include "Orientation.h"
#include "SurfaceFlags.h"
namespace mozilla::image {
class Decoder;
class IDecodingTask;
class nsICODecoder;
class RasterImage;
class SourceBuffer;
class SourceBufferIterator;
class DecoderFactory {
public:
/// @return the type of decoder which is appropriate for @aMimeType.
static DecoderType GetDecoderType(const char* aMimeType);
/// @return the default flags to use when creating a decoder of @aType.
static DecoderFlags GetDefaultDecoderFlagsForType(DecoderType aType);
/**
* Creates and initializes a decoder for non-animated images of type @aType.
* (If the image *is* animated, only the first frame will be decoded.) The
* decoder will send notifications to @aImage.
*
* @param aType Which type of decoder to create - JPEG, PNG, etc.
* @param aImage The image will own the decoder and which should receive
* notifications as decoding progresses.
* @param aSourceBuffer The SourceBuffer which the decoder will read its data
* from.
* @param aIntrinsicSize The intrinsic size of the image, normally obtained
* during the metadata decode.
* @param aOutputSize The output size for the decoder. If this is smaller than
* the intrinsic size, the decoder will downscale the
* image.
* @param aDecoderFlags Flags specifying the behavior of this decoder.
* @param aSurfaceFlags Flags specifying the type of output this decoder
* should produce.
* @param aOutTask Task representing the decoder.
* @return NS_OK if the decoder has been created/initialized successfully;
* NS_ERROR_ALREADY_INITIALIZED if there is already an active decoder
* for this image;
* Else some other unrecoverable error occurred.
*/
static nsresult CreateDecoder(DecoderType aType, NotNull<RasterImage*> aImage,
NotNull<SourceBuffer*> aSourceBuffer,
const gfx::IntSize& aIntrinsicSize,
const gfx::IntSize& aOutputSize,
DecoderFlags aDecoderFlags,
SurfaceFlags aSurfaceFlags,
IDecodingTask** aOutTask);
/**
* Creates and initializes a decoder for animated images of type @aType.
* The decoder will send notifications to @aImage.
*
* @param aType Which type of decoder to create - JPEG, PNG, etc.
* @param aImage The image will own the decoder and which should receive
* notifications as decoding progresses.
* @param aSourceBuffer The SourceBuffer which the decoder will read its data
* from.
* @param aIntrinsicSize The intrinsic size of the image, normally obtained
* during the metadata decode.
* @param aDecoderFlags Flags specifying the behavior of this decoder.
* @param aSurfaceFlags Flags specifying the type of output this decoder
* should produce.
* @param aCurrentFrame The current frame the decoder should auto advance to.
* @param aOutTask Task representing the decoder.
* @return NS_OK if the decoder has been created/initialized successfully;
* NS_ERROR_ALREADY_INITIALIZED if there is already an active decoder
* for this image;
* Else some other unrecoverable error occurred.
*/
static nsresult CreateAnimationDecoder(
DecoderType aType, NotNull<RasterImage*> aImage,
NotNull<SourceBuffer*> aSourceBuffer, const gfx::IntSize& aIntrinsicSize,
DecoderFlags aDecoderFlags, SurfaceFlags aSurfaceFlags,
size_t aCurrentFrame, IDecodingTask** aOutTask);
/**
* Creates and initializes a decoder for animated images, cloned from the
* given decoder.
*
* @param aDecoder Decoder to clone.
*/
static already_AddRefed<Decoder> CloneAnimationDecoder(Decoder* aDecoder);
/**
* Creates and initializes a metadata decoder for an anonymous image, cloned
* from the given decoder.
*
* @param aDecoder Decoder to clone.
*/
static already_AddRefed<Decoder> CloneAnonymousMetadataDecoder(
Decoder* aDecoder, const Maybe<DecoderFlags>& aDecoderFlags = Nothing());
/**
* Creates and initializes a metadata decoder of type @aType. This decoder
* will only decode the image's header, extracting metadata like the size of
* the image. No actual image data will be decoded and no surfaces will be
* allocated. The decoder will send notifications to @aImage.
*
* @param aType Which type of decoder to create - JPEG, PNG, etc.
* @param aImage The image will own the decoder and which should receive
* notifications as decoding progresses.
* @param aSourceBuffer The SourceBuffer which the decoder will read its data
* from.
*/
static already_AddRefed<IDecodingTask> CreateMetadataDecoder(
DecoderType aType, NotNull<RasterImage*> aImage, DecoderFlags aFlags,
NotNull<SourceBuffer*> aSourceBuffer);
/**
* Creates and initializes a decoder for an ICO resource, which may be either
* a BMP or PNG image.
*
* @param aType Which type of decoder to create. This must be either BMP or
* PNG.
* @param aIterator The SourceBufferIterator which the decoder will read its
* data from.
* @param aICODecoder The ICO decoder which is controlling this resource
* decoder. @aICODecoder's settings will be copied to the
* resource decoder, so the two decoders will have the
* same decoder flags, surface flags, target size, and
* other parameters.
* @param aIsMetadataDecode Indicates whether or not this decoder is for
* metadata or not. Independent of the state of the
* parent decoder.
* @param aExpectedSize The expected size of the resource from the ICO header.
* @param aDataOffset If @aType is BMP, specifies the offset at which data
* begins in the BMP resource. Must be Some() if and only
* if @aType is BMP.
*/
static already_AddRefed<Decoder> CreateDecoderForICOResource(
DecoderType aType, SourceBufferIterator&& aIterator,
NotNull<nsICODecoder*> aICODecoder, bool aIsMetadataDecode,
const Maybe<OrientedIntSize>& aExpectedSize,
const Maybe<uint32_t>& aDataOffset = Nothing());
/**
* Creates and initializes an anonymous decoder (one which isn't associated
* with an Image object). Only the first frame of the image will be decoded.
*
* @param aType Which type of decoder to create - JPEG, PNG, etc.
* @param aSourceBuffer The SourceBuffer which the decoder will read its data
* from.
* @param aOutputSize If Some(), the output size for the decoder. If this is
* smaller than the intrinsic size, the decoder will
* downscale the image. If Nothing(), the output size will
* be the intrinsic size.
* @param aDecoderFlags Flags specifying the behavior of this decoder.
* @param aSurfaceFlags Flags specifying the type of output this decoder
* should produce.
*/
static already_AddRefed<Decoder> CreateAnonymousDecoder(
DecoderType aType, NotNull<SourceBuffer*> aSourceBuffer,
const Maybe<gfx::IntSize>& aOutputSize, DecoderFlags aDecoderFlags,
SurfaceFlags aSurfaceFlags);
/**
* Creates and initializes an anonymous metadata decoder (one which isn't
* associated with an Image object). This decoder will only decode the image's
* header, extracting metadata like the size of the image. No actual image
* data will be decoded and no surfaces will be allocated.
*
* @param aType Which type of decoder to create - JPEG, PNG, etc.
* @param aSourceBuffer The SourceBuffer which the decoder will read its data
* from.
* @param aDecoderFlags Flags specifying the behavior of this decoder.
*/
static already_AddRefed<Decoder> CreateAnonymousMetadataDecoder(
DecoderType aType, NotNull<SourceBuffer*> aSourceBuffer,
DecoderFlags aDecoderFlags);
private:
virtual ~DecoderFactory() = 0;
/**
* An internal method which allocates a new decoder of the requested @aType.
*/
static already_AddRefed<Decoder> GetDecoder(DecoderType aType,
RasterImage* aImage,
bool aIsRedecode);
};
} // namespace mozilla::image
#endif // mozilla_image_DecoderFactory_h