gecko-dev/image/DecoderFlags.h
Andrew Osmond fa360dba1b Bug 1901076 - Part 2. Expose frame count variant of metadata decoders. r=tnikkel
It is useful/necessary for WebCodecs image decoding support to be able
to calculate a frame count for the encoded image without actually
decoding every frame. It needs to be able to provide results without the
complete buffer as well.

Differential Revision: https://phabricator.services.mozilla.com/D212831
2024-06-24 22:44:30 +00:00

65 lines
2.1 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_DecoderFlags_h
#define mozilla_image_DecoderFlags_h
#include "mozilla/TypedEnumBits.h"
namespace mozilla {
namespace image {
/**
* Flags that influence decoder behavior. Note that these flags *don't*
* influence the logical content of the surfaces that the decoder generates, so
* they're not in a factor in SurfaceCache lookups and the like. These flags
* instead either influence which surfaces are generated at all or the tune the
* decoder's behavior for a particular scenario.
*/
enum class DecoderFlags : uint8_t {
FIRST_FRAME_ONLY = 1 << 0,
IS_REDECODE = 1 << 1,
IMAGE_IS_TRANSIENT = 1 << 2,
ASYNC_NOTIFY = 1 << 3,
/**
* By default, a surface is considered substitutable. That means callers are
* willing to accept a less than ideal match to display. If a caller requires
* a specific size and won't accept alternatives, then this flag should be
* set.
*/
CANNOT_SUBSTITUTE = 1 << 4,
#ifdef MOZ_AV1
// The flags below are stored in RasterImage to allow a decoded image to
// remain consistent in whether it is animated or not.
// Set according to the "image.avif.sequence.enabled" preference.
AVIF_SEQUENCES_ENABLED = 1 << 5,
// Set according to the
// "image.avif.sequence.animate_avif_major_branded_images" preference.
AVIF_ANIMATE_AVIF_MAJOR = 1 << 6,
#endif
/**
* By default, we don't count how many animated frames there are in an image,
* as that would require us to iterate over the entire buffer for some image
* formats. If the caller requires a full accounting of how many frames there
* are.
*/
COUNT_FRAMES = 1 << 7,
};
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(DecoderFlags)
/**
* @return the default set of decode flags.
*/
inline DecoderFlags DefaultDecoderFlags() { return DecoderFlags(); }
} // namespace image
} // namespace mozilla
#endif // mozilla_image_DecoderFlags_h