ladybird/Libraries/LibWeb/HTML/AnimatedDecodedImageData.h
Andreas Kling 97986f9739 LibWeb: Stream animated image frames on demand
Add AnimatedDecodedImageData which implements DecodedImageData with
an 8-slot buffer pool instead of storing all frames in memory.
Frames are requested on demand from the ImageDecoder service as
the animation progresses.

For a 344-frame animated image at 1920x1080, this reduces
WebContent memory from ~1.3 GB to ~66 MB.

The streaming class owns frame progression and synchronizes
multiple callers (HTMLImageElement and ImageStyleValue) through
notify_frame_advanced() returning the authoritative frame index.
When a frame isn't in the pool, the last displayed frame is shown
as a fallback (brief freeze rather than blank).

Rename the old AnimatedBitmapDecodedImageData (which now only
handles static/single-frame images) to BitmapDecodedImageData.
2026-02-13 18:34:24 +01:00

101 lines
3.2 KiB
C++

/*
* Copyright (c) 2026, Andreas Kling <andreas@ladybird.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Array.h>
#include <AK/HashMap.h>
#include <LibGC/Ptr.h>
#include <LibGfx/ColorSpace.h>
#include <LibGfx/Forward.h>
#include <LibWeb/HTML/DecodedImageData.h>
namespace Web::HTML {
class AnimatedDecodedImageData final : public DecodedImageData {
GC_CELL(AnimatedDecodedImageData, DecodedImageData);
GC_DECLARE_ALLOCATOR(AnimatedDecodedImageData);
public:
static constexpr bool OVERRIDES_FINALIZE = true;
static GC::Ref<AnimatedDecodedImageData> create(
JS::Realm&,
i64 session_id,
u32 frame_count,
u32 loop_count,
Gfx::IntSize,
Gfx::ColorSpace,
Vector<u32> durations,
Vector<NonnullRefPtr<Gfx::Bitmap>> initial_bitmaps);
virtual ~AnimatedDecodedImageData() override;
virtual void finalize() override;
virtual RefPtr<Gfx::ImmutableBitmap> bitmap(size_t frame_index, Gfx::IntSize = {}) const override;
virtual int frame_duration(size_t frame_index) const override;
virtual size_t frame_count() const override { return m_frame_count; }
virtual size_t loop_count() const override { return m_loop_count; }
virtual bool is_animated() const override { return true; }
virtual Optional<CSSPixels> intrinsic_width() const override;
virtual Optional<CSSPixels> intrinsic_height() const override;
virtual Optional<CSSPixelFraction> intrinsic_aspect_ratio() const override;
virtual Optional<Gfx::IntRect> frame_rect(size_t frame_index) const override;
virtual void paint(DisplayListRecordingContext&, size_t frame_index, Gfx::IntRect dst_rect, Gfx::IntRect clip_rect, Gfx::ScalingMode) const override;
virtual size_t notify_frame_advanced(size_t caller_frame_index) override;
void receive_frames(Vector<NonnullRefPtr<Gfx::Bitmap>>, u32 start_frame_index);
i64 session_id() const { return m_session_id; }
static void deliver_frames_for_session(i64 session_id, Vector<NonnullRefPtr<Gfx::Bitmap>>);
static void install_frame_delivery_callback();
private:
static HashMap<i64, GC::RawPtr<AnimatedDecodedImageData>>& session_registry();
static constexpr u32 BUFFER_POOL_SIZE = 8;
static constexpr u32 REQUEST_BATCH_SIZE = 4;
struct BufferSlot {
Optional<u32> frame_index;
RefPtr<Gfx::ImmutableBitmap> bitmap;
u64 generation { 0 };
};
AnimatedDecodedImageData(
i64 session_id,
u32 frame_count,
u32 loop_count,
Gfx::IntSize,
Gfx::ColorSpace,
Vector<u32> durations);
BufferSlot const* find_slot(u32 frame_index) const;
BufferSlot& evict_oldest_slot();
void maybe_request_more_frames(size_t current_frame_index);
i64 m_session_id;
u32 m_frame_count;
u32 m_loop_count;
Gfx::IntSize m_size;
Gfx::ColorSpace m_color_space;
Vector<u32> m_durations;
Array<BufferSlot, BUFFER_POOL_SIZE> m_buffer_slots;
mutable RefPtr<Gfx::ImmutableBitmap> m_last_displayed_bitmap;
u64 m_write_generation { 0 };
bool m_request_in_flight { false };
u32 m_current_frame_index { 0 };
u32 m_last_requested_start_frame { 0 };
u32 m_highest_requested_frame { 0 };
};
}