Show first frame of webm in photo editor.

Telegram/SourceFiles/editor/scene/scene_item_sticker.cpp

@@ -34,9 +34,9 @@ ItemSticker::ItemSticker(
 	}
 	const auto updateThumbnail = [=] {
 		const auto guard = gsl::finally([&] {
-			setAspectRatio(_pixmap.isNull()
-				? 1.0
-				: (_pixmap.height() / float64(_pixmap.width())));
+			if (_pixmap.isNull()) {
+				setAspectRatio(1.);
+			}
 		});
 		if (stickerData->isLottie()) {
 			_lottie.player = ChatHelpers::LottiePlayerFromDocument(
@@ -54,6 +54,25 @@ ItemSticker::ItemSticker(
 				update();
 			}, _lottie.lifetime);
 			return true;
+		} else if (stickerData->isWebm()
+			&& !_document->dimensions.isEmpty()) {
+			const auto callback = [=](::Media::Clip::Notification) {
+				const auto size = _document->dimensions;
+				if (_webm && _webm->ready() && !_webm->started()) {
+					_webm->start({ .frame = size, .keepAlpha = true });
+				}
+				if (_webm && _webm->started()) {
+					updatePixmap(_webm->current(
+						{ .frame = size, .keepAlpha = true },
+						0));
+					_webm = nullptr;
+				}
+			};
+			_webm = ::Media::Clip::MakeReader(
+				_mediaView->owner()->location(),
+				_mediaView->bytes(),
+				callback);
+			return true;
 		}
 		const auto sticker = _mediaView->getStickerLarge();
 		if (!sticker) {
@@ -83,6 +102,9 @@ void ItemSticker::updatePixmap(QPixmap &&pixmap) {
 	} else {
 		update();
 	}
+	if (!_pixmap.isNull()) {
+		setAspectRatio(_pixmap.height() / float64(_pixmap.width()));
+	}
 }
 
 void ItemSticker::paint(

Telegram/SourceFiles/editor/scene/scene_item_sticker.h

@@ -8,6 +8,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #pragma once
 
 #include "editor/scene/scene_item_base.h"
+#include "media/clip/media_clip_reader.h"
 
 namespace Data {
 class DocumentMedia;
@@ -47,6 +48,7 @@ private:
 		std::unique_ptr<Lottie::SinglePlayer> player;
 		rpl::lifetime lifetime;
 	} _lottie;
+	::Media::Clip::ReaderPointer _webm;
 	QPixmap _pixmap;
 
 	rpl::lifetime _loadingLifetime;