Implement Lottie::MultiPlayer.

Telegram/SourceFiles/base/algorithm.h

@@ -30,6 +30,44 @@ inline bool contains(const Container &container, const T &value) {
 	return std::find(std::begin(container), end, value) != end;
 }
 
+// We need a custom comparator for set<std::unique_ptr<T>>::find to work with pointers.
+// thanks to http://stackoverflow.com/questions/18939882/raw-pointer-lookup-for-sets-of-unique-ptrs
+template <typename T>
+struct pointer_comparator {
+	using is_transparent = std::true_type;
+
+	// helper does some magic in order to reduce the number of
+	// pairs of types we need to know how to compare: it turns
+	// everything into a pointer, and then uses `std::less<T*>`
+	// to do the comparison:
+	struct helper {
+		const T *ptr = nullptr;
+		helper() = default;
+		helper(const helper &other) = default;
+		helper(const T *p) : ptr(p) {
+		}
+		template <typename ...Ts>
+		helper(const std::shared_ptr<Ts...> &other) : ptr(other.get()) {
+		}
+		template <typename ...Ts>
+		helper(const std::unique_ptr<Ts...> &other) : ptr(other.get()) {
+		}
+		bool operator<(helper other) const {
+			return std::less<const T*>()(ptr, other.ptr);
+		}
+	};
+
+	// without helper, we'd need 2^n different overloads, where
+	// n is the number of types we want to support (so, 8 with
+	// raw pointers, unique pointers, and shared pointers).  That
+	// seems silly.
+	// && helps enforce rvalue use only
+	bool operator()(const helper &&lhs, const helper &&rhs) const {
+		return lhs < rhs;
+	}
+
+};
+
 } // namespace base
 
 template <typename T>

Telegram/SourceFiles/base/flat_map.h

@@ -53,12 +53,19 @@ struct flat_multi_map_pair_type {
 	, second(std::forward<OtherValue>(value)) {
 	}
 
-	flat_multi_map_pair_type(const flat_multi_map_pair_type&) = default;
-	flat_multi_map_pair_type(flat_multi_map_pair_type&&) = default;
+	flat_multi_map_pair_type(const flat_multi_map_pair_type &pair)
+	: first(pair.first)
+	, second(pair.second) {
+	}
+
+	flat_multi_map_pair_type(flat_multi_map_pair_type &&pair)
+	: first(std::move(const_cast<Key&>(pair.first)))
+	, second(std::move(pair.second)) {
+	}
 
 	flat_multi_map_pair_type &operator=(const flat_multi_map_pair_type&) = delete;
 	flat_multi_map_pair_type &operator=(flat_multi_map_pair_type &&other) {
-		const_cast<Key&>(first) = other.first;
+		const_cast<Key&>(first) = std::move(const_cast<Key&>(other.first));
 		second = std::move(other.second);
 		return *this;
 	}
@@ -474,6 +481,28 @@ public:
 		return compare()(key, where->first) ? impl().end() : where;
 	}
 
+	template <typename OtherKey, typename = typename Compare::is_transparent>
+	iterator findFirst(const OtherKey &key) {
+		if (empty()
+			|| compare()(key, front().first)
+			|| compare()(back().first, key)) {
+			return end();
+		}
+		auto where = getLowerBound(key);
+		return compare()(key, where->first) ? impl().end() : where;
+	}
+
+	template <typename OtherKey, typename = typename Compare::is_transparent>
+	const_iterator findFirst(const OtherKey &key) const {
+		if (empty()
+			|| compare()(key, front().first)
+			|| compare()(back().first, key)) {
+			return end();
+		}
+		auto where = getLowerBound(key);
+		return compare()(key, where->first) ? impl().end() : where;
+	}
+
 	bool contains(const Key &key) const {
 		return findFirst(key) != end();
 	}
@@ -558,48 +587,54 @@ private:
 		return _data.elements;
 	}
 
-	typename impl_t::iterator getLowerBound(const Key &key) {
+	template <typename OtherKey>
+	typename impl_t::iterator getLowerBound(const OtherKey &key) {
 		return std::lower_bound(
 			std::begin(impl()),
 			std::end(impl()),
 			key,
 			compare());
 	}
-	typename impl_t::const_iterator getLowerBound(const Key &key) const {
+	template <typename OtherKey>
+	typename impl_t::const_iterator getLowerBound(const OtherKey &key) const {
 		return std::lower_bound(
 			std::begin(impl()),
 			std::end(impl()),
 			key,
 			compare());
 	}
-	typename impl_t::iterator getUpperBound(const Key &key) {
+	template <typename OtherKey>
+	typename impl_t::iterator getUpperBound(const OtherKey &key) {
 		return std::upper_bound(
 			std::begin(impl()),
 			std::end(impl()),
 			key,
 			compare());
 	}
-	typename impl_t::const_iterator getUpperBound(const Key &key) const {
+	template <typename OtherKey>
+	typename impl_t::const_iterator getUpperBound(const OtherKey &key) const {
 		return std::upper_bound(
 			std::begin(impl()),
 			std::end(impl()),
 			key,
 			compare());
 	}
+	template <typename OtherKey>
 	std::pair<
 		typename impl_t::iterator,
 		typename impl_t::iterator
-	> getEqualRange(const Key &key) {
+	> getEqualRange(const OtherKey &key) {
 		return std::equal_range(
 			std::begin(impl()),
 			std::end(impl()),
 			key,
 			compare());
 	}
+	template <typename OtherKey>
 	std::pair<
 		typename impl_t::const_iterator,
 		typename impl_t::const_iterator
-	> getEqualRange(const Key &key) const {
+	> getEqualRange(const OtherKey &key) const {
 		return std::equal_range(
 			std::begin(impl()),
 			std::end(impl()),
@@ -720,12 +755,12 @@ public:
 		where->second = std::move(value);
 		return { where, false };
 	}
-	template <typename... Args>
+	template <typename OtherKey, typename... Args>
 	std::pair<iterator, bool> emplace(
-			const Key &key,
+			OtherKey &&key,
 			Args&&... args) {
 		return this->insert(value_type(
-			key,
+			std::forward<OtherKey>(key),
 			Type(std::forward<Args>(args)...)));
 	}
 	template <typename... Args>
@@ -775,6 +810,14 @@ public:
 	const_iterator find(const Key &key) const {
 		return this->findFirst(key);
 	}
+	template <typename OtherKey, typename = typename Compare::is_transparent>
+	iterator find(const OtherKey &key) {
+		return this->findFirst<OtherKey>(key);
+	}
+	template <typename OtherKey, typename = typename Compare::is_transparent>
+	const_iterator find(const OtherKey &key) const {
+		return this->findFirst<OtherKey>(key);
+	}
 
 	Type &operator[](const Key &key) {
 		if (this->empty() || this->compare()(key, this->front().first)) {

Telegram/SourceFiles/base/flat_map_tests.cpp

@@ -69,10 +69,10 @@ TEST_CASE("simple flat_maps tests", "[flat_map]") {
 
 TEST_CASE("flat_maps custom comparator", "[flat_map]") {
 	base::flat_map<int_wrap, string, int_wrap_comparator> v;
-	v.emplace({ 0 }, "a");
-	v.emplace({ 5 }, "b");
-	v.emplace({ 4 }, "d");
-	v.emplace({ 2 }, "e");
+	v.emplace(int_wrap{ 0 }, "a");
+	v.emplace(int_wrap{ 5 }, "b");
+	v.emplace(int_wrap{ 4 }, "d");
+	v.emplace(int_wrap{ 2 }, "e");
 
 	auto checkSorted = [&] {
 		auto prev = v.begin();
@@ -85,7 +85,7 @@ TEST_CASE("flat_maps custom comparator", "[flat_map]") {
 	checkSorted();
 
 	SECTION("adding item puts it in the right position") {
-		v.emplace({ 3 }, "c");
+		v.emplace(int_wrap{ 3 }, "c");
 		REQUIRE(v.size() == 5);
 		REQUIRE(v.find({ 3 }) != v.end());
 		checkSorted();

Telegram/SourceFiles/core/utils.h

@@ -36,44 +36,6 @@ inline constexpr D up_cast(T object) {
 	}
 }
 
-// We need a custom comparator for std::set<std::unique_ptr<T>>::find to work with pointers.
-// thanks to http://stackoverflow.com/questions/18939882/raw-pointer-lookup-for-sets-of-unique-ptrs
-template <typename T>
-struct pointer_comparator {
-	using is_transparent = std::true_type;
-
-	// helper does some magic in order to reduce the number of
-	// pairs of types we need to know how to compare: it turns
-	// everything into a pointer, and then uses `std::less<T*>`
-	// to do the comparison:
-	struct helper {
-		T *ptr = nullptr;
-		helper() = default;
-		helper(const helper &other) = default;
-		helper(T *p) : ptr(p) {
-		}
-		template <typename ...Ts>
-		helper(const std::shared_ptr<Ts...> &other) : ptr(other.get()) {
-		}
-		template <typename ...Ts>
-		helper(const std::unique_ptr<Ts...> &other) : ptr(other.get()) {
-		}
-		bool operator<(helper other) const {
-			return std::less<T*>()(ptr, other.ptr);
-		}
-	};
-
-	// without helper, we'd need 2^n different overloads, where
-	// n is the number of types we want to support (so, 8 with
-	// raw pointers, unique pointers, and shared pointers).  That
-	// seems silly.
-	// && helps enforce rvalue use only
-	bool operator()(const helper &&lhs, const helper &&rhs) const {
-		return lhs < rhs;
-	}
-
-};
-
 template <typename T>
 using set_of_unique_ptr = std::set<std::unique_ptr<T>, base::pointer_comparator<T>>;
 

Telegram/SourceFiles/lottie/lottie_animation.h

@@ -10,12 +10,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "lottie/lottie_common.h"
 #include "base/weak_ptr.h"
 
-#include <QSize>
-#include <crl/crl_time.h>
-#include <rpl/event_stream.h>
-#include <vector>
-#include <optional>
-
 class QImage;
 class QString;
 class QByteArray;
@@ -28,7 +22,6 @@ namespace Lottie {
 
 class Player;
 class SharedState;
-class FrameRenderer;
 
 QImage ReadThumbnail(const QByteArray &content);
 

Telegram/SourceFiles/lottie/lottie_common.h

@@ -27,16 +27,6 @@ struct Information {
 	QSize size;
 };
 
-struct DisplayFrameRequest {
-	crl::time time = 0;
-};
-
-struct Update {
-	base::variant<
-		Information,
-		DisplayFrameRequest> data;
-};
-
 enum class Error {
 	ParseFailed,
 	NotSupported,

Telegram/SourceFiles/lottie/lottie_frame_renderer.cpp

@@ -49,7 +49,7 @@ public:
 		crl::weak_on_queue<FrameRendererObject> weak);
 
 	void append(std::unique_ptr<SharedState> entry);
-	void frameShown(not_null<SharedState*> entry);
+	void frameShown();
 	void updateFrameRequest(
 		not_null<SharedState*> entry,
 		const FrameRequest &request);
@@ -140,7 +140,7 @@ void FrameRendererObject::append(std::unique_ptr<SharedState> state) {
 	queueGenerateFrames();
 }
 
-void FrameRendererObject::frameShown(not_null<SharedState*> entry) {
+void FrameRendererObject::frameShown() {
 	queueGenerateFrames();
 }
 
@@ -423,28 +423,29 @@ crl::time SharedState::nextFrameDisplayTime() const {
 	Unexpected("Counter value in VideoTrack::Shared::nextFrameDisplayTime.");
 }
 
-crl::time SharedState::markFrameDisplayed(crl::time now) {
+crl::time SharedState::markFrameDisplayed(crl::time now, crl::time delayed) {
 	const auto mark = [&](int counter) {
 		const auto next = (counter + 1) % (2 * kFramesCount);
 		const auto index = next / 2;
 		const auto frame = getFrame(index);
 		Assert(frame->position != kTimeUnknown);
-		Assert(frame->displayed == kTimeUnknown);
 
+		if (frame->displayed != kTimeUnknown) {
+			return kTimeUnknown;
+		}
 		frame->displayed = now;
-		_accumulatedDelayMs += (frame->displayed - frame->display);
-
 		return frame->position;
 	};
 
+	_accumulatedDelayMs += delayed;
 	switch (counter()) {
-	case 0: Unexpected("Value 0 in SharedState::markFrameDisplayed.");
+	case 0: return kTimeUnknown;
 	case 1: return mark(1);
-	case 2: Unexpected("Value 2 in SharedState::markFrameDisplayed.");
+	case 2: return kTimeUnknown;
 	case 3: return mark(3);
-	case 4: Unexpected("Value 4 in SharedState::markFrameDisplayed.");
+	case 4: return kTimeUnknown;
 	case 5: return mark(5);
-	case 6: Unexpected("Value 6 in SharedState::markFrameDisplayed.");
+	case 6: return kTimeUnknown;
 	case 7: return mark(7);
 	}
 	Unexpected("Counter value in Lottie::SharedState::markFrameDisplayed.");
@@ -480,11 +481,15 @@ crl::time SharedState::markFrameShown() {
 
 SharedState::~SharedState() = default;
 
+std::shared_ptr<FrameRenderer> FrameRenderer::CreateIndependent() {
+	return std::make_shared<FrameRenderer>();
+}
+
 std::shared_ptr<FrameRenderer> FrameRenderer::Instance() {
 	if (auto result = GlobalInstance.lock()) {
 		return result;
 	}
-	auto result = std::make_shared<FrameRenderer>();
+	auto result = CreateIndependent();
 	GlobalInstance = result;
 	return result;
 }
@@ -496,9 +501,9 @@ void FrameRenderer::append(std::unique_ptr<SharedState> entry) {
 	});
 }
 
-void FrameRenderer::frameShown(not_null<SharedState*> entry) {
+void FrameRenderer::frameShown() {
 	_wrapped.with([=](FrameRendererObject &unwrapped) {
-		unwrapped.frameShown(entry);
+		unwrapped.frameShown();
 	});
 }
 

Telegram/SourceFiles/lottie/lottie_frame_renderer.h

@@ -62,7 +62,7 @@ public:
 
 	[[nodiscard]] not_null<Frame*> frameForPaint();
 	[[nodiscard]] crl::time nextFrameDisplayTime() const;
-	crl::time markFrameDisplayed(crl::time now);
+	crl::time markFrameDisplayed(crl::time now, crl::time delayed);
 	crl::time markFrameShown();
 
 	void renderFrame(QImage &image, const FrameRequest &request, int index);
@@ -108,6 +108,7 @@ class FrameRendererObject;
 
 class FrameRenderer final {
 public:
+	static std::shared_ptr<FrameRenderer> CreateIndependent();
 	static std::shared_ptr<FrameRenderer> Instance();
 
 	void append(std::unique_ptr<SharedState> entry);
@@ -115,7 +116,7 @@ public:
 	void updateFrameRequest(
 		not_null<SharedState*> entry,
 		const FrameRequest &request);
-	void frameShown(not_null<SharedState*> entry);
+	void frameShown();
 	void remove(not_null<SharedState*> state);
 
 private:

Telegram/SourceFiles/lottie/lottie_multi_player.cpp

@@ -0,0 +1,203 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#include "lottie/lottie_multi_player.h"
+
+#include "lottie/lottie_frame_renderer.h"
+#include "lottie/lottie_animation.h"
+
+#include <range/v3/algorithm/remove.hpp>
+
+namespace Lottie {
+
+std::shared_ptr<FrameRenderer> MakeFrameRenderer() {
+	return FrameRenderer::CreateIndependent();
+}
+
+MultiPlayer::MultiPlayer(std::shared_ptr<FrameRenderer> renderer)
+: _renderer(renderer ? std::move(renderer) : FrameRenderer::Instance()) {
+}
+
+MultiPlayer::~MultiPlayer() {
+	for (const auto &[animation, state] : _active) {
+		_renderer->remove(state);
+	}
+}
+
+not_null<Animation*> MultiPlayer::append(
+		FnMut<void(FnMut<void(QByteArray &&cached)>)> get, // Main thread.
+		FnMut<void(QByteArray &&cached)> put, // Unknown thread.
+		const QByteArray &content,
+		const FrameRequest &request) {
+	_animations.push_back(std::make_unique<Animation>(
+		this,
+		std::move(get),
+		std::move(put),
+		content,
+		request));
+	return _animations.back().get();
+}
+
+not_null<Animation*> MultiPlayer::append(
+		const QByteArray &content,
+		const FrameRequest &request) {
+	_animations.push_back(std::make_unique<Animation>(
+		this,
+		content,
+		request));
+	return _animations.back().get();
+}
+
+crl::time MultiPlayer::startAtRightTime(not_null<SharedState*> state) {
+	Expects(!_active.empty());
+	Expects((_active.size() == 1) == (_started == kTimeUnknown));
+
+	if (_active.size() == 1) {
+		_started = crl::now();
+		state->start(this, _started);
+		return _started;
+	}
+
+	const auto now = crl::now();
+	const auto rate = state->information().frameRate;
+	Assert(rate != 0);
+
+	const auto started = _started + _accumulatedDelay;
+	const auto skipFrames = (now - started) * rate / 1000;
+	const auto startAt = started + (1000 * skipFrames / rate);
+
+	state->start(this, startAt);
+	return startAt;
+}
+
+void MultiPlayer::start(
+		not_null<Animation*> animation,
+		std::unique_ptr<SharedState> state) {
+	Expects(state != nullptr);
+
+	_active.emplace(animation, state.get());
+
+	auto information = state->information();
+	startAtRightTime(state.get());
+	_renderer->append(std::move(state));
+	_updates.fire({});
+
+	crl::on_main_update_requests(
+	) | rpl::start_with_next([=] {
+		checkStep();
+	}, _lifetime);
+
+	_nextFrameTime = kTimeUnknown;
+	_timer.cancel();
+	checkStep();
+}
+
+void MultiPlayer::remove(not_null<Animation*> animation) {
+	const auto i = _active.find(animation);
+	if (i != end(_active)) {
+		_renderer->remove(i->second);
+	}
+	_animations.erase(
+		ranges::remove(
+			_animations,
+			animation.get(),
+			&std::unique_ptr<Animation>::get),
+		end(_animations));
+
+	if (_active.empty()) {
+		_started = kTimeUnknown;
+		_accumulatedDelay = 0;
+		_nextFrameTime = kTimeUnknown;
+		_timer.cancel();
+	}
+}
+
+void MultiPlayer::failed(not_null<Animation*> animation, Error error) {
+	//_updates.fire({ animation, error });
+}
+
+rpl::producer<MultiUpdate> MultiPlayer::updates() const {
+	return _updates.events();
+}
+
+void MultiPlayer::checkStep() {
+	if (_nextFrameTime != kTimeUnknown) {
+		checkNextFrameRender();
+	} else {
+		checkNextFrameAvailability();
+	}
+}
+
+void MultiPlayer::checkNextFrameAvailability() {
+	if (_active.empty()) {
+		return;
+	}
+	auto next = kTimeUnknown;
+	for (const auto &[animation, state] : _active) {
+		const auto time = state->nextFrameDisplayTime();
+		if (time == kTimeUnknown) {
+			return;
+		}
+		if (next == kTimeUnknown || next > time) {
+			next = time;
+		}
+	}
+	Assert(next != kTimeUnknown);
+	_nextFrameTime = next;
+	checkNextFrameRender();
+}
+
+void MultiPlayer::checkNextFrameRender() {
+	Expects(_nextFrameTime != kTimeUnknown);
+
+	const auto now = crl::now();
+	if (now < _nextFrameTime) {
+		if (!_timer.isActive()) {
+			_timer.callOnce(_nextFrameTime - now);
+		}
+	} else {
+		_timer.cancel();
+
+		const auto exact = std::exchange(_nextFrameTime, kTimeUnknown);
+		markFrameDisplayed(now, now - exact);
+		_updates.fire({});
+		checkStep();
+	}
+}
+
+void MultiPlayer::updateFrameRequest(
+		not_null<const Animation*> animation,
+		const FrameRequest &request) {
+	const auto i = _active.find(animation.get());
+	Assert(i != _active.end());
+
+	_renderer->updateFrameRequest(i->second, request);
+}
+
+void MultiPlayer::markFrameDisplayed(crl::time now, crl::time delayed) {
+	Expects(!_active.empty());
+
+	for (const auto &[animation, state] : _active) {
+		const auto time = state->nextFrameDisplayTime();
+		Assert(time != kTimeUnknown);
+		if (now >= time) {
+			state->markFrameDisplayed(now, delayed);
+		}
+	}
+}
+
+void MultiPlayer::markFrameShown() {
+	if (_active.empty()) {
+		return;
+	}
+	for (const auto &[animation, state] : _active) {
+		state->markFrameShown();
+	}
+	_renderer->frameShown();
+}
+
+} // namespace Lottie

Telegram/SourceFiles/lottie/lottie_multi_player.h

@@ -0,0 +1,77 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#pragma once
+
+#include "lottie/lottie_player.h"
+#include "base/timer.h"
+#include "base/algorithm.h"
+
+#include <rpl/event_stream.h>
+
+namespace Lottie {
+
+class Animation;
+class FrameRenderer;
+
+struct MultiUpdate {
+	//base::variant<
+	//	std::pair<Animation*, Information>,
+	//	DisplayMultiFrameRequest,
+	//	std::pair<Animation*, Error>> data;
+};
+
+std::shared_ptr<FrameRenderer> MakeFrameRenderer();
+
+class MultiPlayer final : public Player {
+public:
+	explicit MultiPlayer(std::shared_ptr<FrameRenderer> renderer = nullptr);
+	~MultiPlayer();
+
+	void start(
+		not_null<Animation*> animation,
+		std::unique_ptr<SharedState> state) override;
+	void failed(not_null<Animation*> animation, Error error) override;
+	void updateFrameRequest(
+		not_null<const Animation*> animation,
+		const FrameRequest &request) override;
+	void markFrameShown() override;
+	void checkStep() override;
+
+	not_null<Animation*> append(
+		FnMut<void(FnMut<void(QByteArray &&cached)>)> get, // Main thread.
+		FnMut<void(QByteArray &&cached)> put, // Unknown thread.
+		const QByteArray &content,
+		const FrameRequest &request);
+	not_null<Animation*> append(
+		const QByteArray &content,
+		const FrameRequest &request);
+
+	rpl::producer<MultiUpdate> updates() const;
+
+	void remove(not_null<Animation*> animation);
+
+private:
+	crl::time startAtRightTime(not_null<SharedState*> state);
+	void markFrameDisplayed(crl::time now, crl::time delayed);
+	void checkNextFrameAvailability();
+	void checkNextFrameRender();
+
+	base::Timer _timer;
+	const std::shared_ptr<FrameRenderer> _renderer;
+	std::vector<std::unique_ptr<Animation>> _animations;
+	base::flat_map<not_null<Animation*>, not_null<SharedState*>> _active;
+	//base::flat_map<not_null<Animation*>, not_null<SharedState*>> _paused;
+	crl::time _started = kTimeUnknown;
+	crl::time _accumulatedDelay = 0;
+	crl::time _nextFrameTime = kTimeUnknown;
+	rpl::event_stream<MultiUpdate> _updates;
+	rpl::lifetime _lifetime;
+
+};
+
+} // namespace Lottie

Telegram/SourceFiles/lottie/lottie_player.h

@@ -22,17 +22,10 @@ public:
 		not_null<Animation*> animation,
 		std::unique_ptr<SharedState> state) = 0;
 	virtual void failed(not_null<Animation*> animation, Error error) = 0;
-
-	[[nodiscard]] virtual rpl::producer<Update, Error> updates() = 0;
-
 	virtual void updateFrameRequest(
 		not_null<const Animation*> animation,
 		const FrameRequest &request) = 0;
-
-	// Returns frame position, if any frame was marked as displayed.
-	virtual crl::time markFrameDisplayed(crl::time now) = 0;
-	virtual crl::time markFrameShown() = 0;
-
+	virtual void markFrameShown() = 0;
 	virtual void checkStep() = 0;
 
 	virtual ~Player() = default;

Telegram/SourceFiles/lottie/lottie_single_player.cpp

@@ -10,9 +10,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "lottie/lottie_frame_renderer.h"
 
 namespace Lottie {
-namespace {
-
-} // namespace
 
 SinglePlayer::SinglePlayer(
 	const QByteArray &content,
@@ -32,6 +29,12 @@ SinglePlayer::SinglePlayer(
 , _renderer(FrameRenderer::Instance()) {
 }
 
+SinglePlayer::~SinglePlayer() {
+	if (_state) {
+		_renderer->remove(_state);
+	}
+}
+
 void SinglePlayer::start(
 		not_null<Animation*> animation,
 		std::unique_ptr<SharedState> state) {
@@ -40,7 +43,6 @@ void SinglePlayer::start(
 	_state = state.get();
 	auto information = state->information();
 	state->start(this, crl::now());
-	_renderer = FrameRenderer::Instance();
 	_renderer->append(std::move(state));
 	_updates.fire({ std::move(information) });
 
@@ -56,13 +58,7 @@ void SinglePlayer::failed(not_null<Animation*> animation, Error error) {
 	_updates.fire_error(std::move(error));
 }
 
-SinglePlayer::~SinglePlayer() {
-	if (_state) {
-		_renderer->remove(_state);
-	}
-}
-
-rpl::producer<Update, Error> SinglePlayer::updates() {
+rpl::producer<Update, Error> SinglePlayer::updates() const {
 	return _updates.events();
 }
 
@@ -87,7 +83,7 @@ void SinglePlayer::checkNextFrameAvailability() {
 
 	_nextFrameTime = _state->nextFrameDisplayTime();
 	if (_nextFrameTime != kTimeUnknown) {
-		checkStep();
+		checkNextFrameRender();
 	}
 }
 
@@ -102,8 +98,8 @@ void SinglePlayer::checkNextFrameRender() {
 	} else {
 		_timer.cancel();
 
-		_nextFrameTime = kTimeUnknown;
-		const auto position = markFrameDisplayed(now);
+		const auto exact = std::exchange(_nextFrameTime, kTimeUnknown);
+		const auto position = _state->markFrameDisplayed(now, now - exact);
 		_updates.fire({ DisplayFrameRequest{ position } });
 	}
 }
@@ -117,19 +113,11 @@ void SinglePlayer::updateFrameRequest(
 	_renderer->updateFrameRequest(_state, request);
 }
 
-crl::time SinglePlayer::markFrameDisplayed(crl::time now) {
+void SinglePlayer::markFrameShown() {
 	Expects(_state != nullptr);
 
-	return _state->markFrameDisplayed(now);
-}
-
-crl::time SinglePlayer::markFrameShown() {
-	Expects(_renderer != nullptr);
-
-	const auto result = _state->markFrameShown();
-	_renderer->frameShown(_state);
-
-	return result;
+	_state->markFrameShown();
+	_renderer->frameShown();
 }
 
 } // namespace Lottie

Telegram/SourceFiles/lottie/lottie_single_player.h

@@ -11,8 +11,22 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "lottie/lottie_animation.h"
 #include "base/timer.h"
 
+#include <rpl/event_stream.h>
+
 namespace Lottie {
 
+class FrameRenderer;
+
+struct DisplayFrameRequest {
+	crl::time time = 0;
+};
+
+struct Update {
+	base::variant<
+		Information,
+		DisplayFrameRequest> data;
+};
+
 class SinglePlayer final : public Player {
 public:
 	SinglePlayer(
@@ -29,29 +43,24 @@ public:
 		not_null<Animation*> animation,
 		std::unique_ptr<SharedState> state) override;
 	void failed(not_null<Animation*> animation, Error error) override;
-
-	rpl::producer<Update, Error> updates() override;
-
-	[[nodiscard]] bool ready() const;
-	[[nodiscard]] QImage frame(const FrameRequest &request) const;
-
 	void updateFrameRequest(
 		not_null<const Animation*> animation,
 		const FrameRequest &request) override;
-
-	// Returns frame position, if any frame was marked as displayed.
-	crl::time markFrameDisplayed(crl::time now) override;
-	crl::time markFrameShown() override;
-
+	void markFrameShown() override;
 	void checkStep() override;
 
+	rpl::producer<Update, Error> updates() const;
+
+	[[nodiscard]] bool ready() const;
+	[[nodiscard]] QImage frame(const FrameRequest &request) const;
+
 private:
 	void checkNextFrameAvailability();
 	void checkNextFrameRender();
 
 	Animation _animation;
 	base::Timer _timer;
-	std::shared_ptr<FrameRenderer> _renderer;
+	const std::shared_ptr<FrameRenderer> _renderer;
 	SharedState *_state = nullptr;
 	crl::time _nextFrameTime = kTimeUnknown;
 	rpl::event_stream<Update, Error> _updates;

Telegram/SourceFiles/media/streaming/media_streaming_player.cpp

@@ -111,7 +111,7 @@ void Player::checkNextFrameAvailability() {
 
 	_nextFrameTime = _video->nextFrameDisplayTime();
 	if (_nextFrameTime != kTimeUnknown) {
-		checkVideoStep();
+		checkNextFrameRender();
 	}
 }
 

Telegram/gyp/lib_lottie.gyp

@@ -64,6 +64,8 @@
       '<(src_loc)/lottie/lottie_common.h',
       '<(src_loc)/lottie/lottie_frame_renderer.cpp',
       '<(src_loc)/lottie/lottie_frame_renderer.h',
+      '<(src_loc)/lottie/lottie_multi_player.cpp',
+      '<(src_loc)/lottie/lottie_multi_player.h',
       '<(src_loc)/lottie/lottie_player.h',
       '<(src_loc)/lottie/lottie_single_player.cpp',
       '<(src_loc)/lottie/lottie_single_player.h',