Don't recompress some JPEGs when sending as photos.

If JPEG is saved in progressive mode and has bpp <= 4
and max(width, height) <= 1280 then we send original bytes.

Telegram/SourceFiles/storage/localimageloader.cpp

@@ -25,6 +25,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "history/history_item.h"
 #include "boxes/send_files_box.h"
 #include "ui/boxes/confirm_box.h"
+#include "ui/image/image_prepare.h"
 #include "lang/lang_keys.h"
 #include "storage/file_download.h"
 #include "storage/storage_media_prepare.h"
@@ -42,6 +43,7 @@ namespace {
 constexpr auto kThumbnailQuality = 87;
 constexpr auto kThumbnailSize = 320;
 constexpr auto kPhotoUploadPartSize = 32 * 1024;
+constexpr auto kRecompressAfterBpp = 4;
 
 using Ui::ValidateThumbDimensions;
 
@@ -53,7 +55,7 @@ struct PreparedFileThumbnail {
 	MTPPhotoSize mtpSize = MTP_photoSizeEmpty(MTP_string());
 };
 
-PreparedFileThumbnail PrepareFileThumbnail(QImage &&original) {
+[[nodiscard]] PreparedFileThumbnail PrepareFileThumbnail(QImage &&original) {
 	const auto width = original.width();
 	const auto height = original.height();
 	if (!ValidateThumbDimensions(width, height)) {
@@ -87,7 +89,9 @@ PreparedFileThumbnail PrepareFileThumbnail(QImage &&original) {
 	return result;
 }
 
-bool FileThumbnailUploadRequired(const QString &filemime, int32 filesize) {
+[[nodiscard]] bool FileThumbnailUploadRequired(
+		const QString &filemime,
+		int32 filesize) {
 	constexpr auto kThumbnailUploadBySize = 5 * 1024 * 1024;
 	const auto kThumbnailKnownMimes = {
 		"image/jpeg",
@@ -101,7 +105,7 @@ bool FileThumbnailUploadRequired(const QString &filemime, int32 filesize) {
 			== end(kThumbnailKnownMimes));
 }
 
-PreparedFileThumbnail FinalizeFileThumbnail(
+[[nodiscard]] PreparedFileThumbnail FinalizeFileThumbnail(
 		PreparedFileThumbnail &&prepared,
 		const QString &filemime,
 		int32 filesize,
@@ -115,7 +119,7 @@ PreparedFileThumbnail FinalizeFileThumbnail(
 	return std::move(prepared);
 }
 
-auto FindAlbumItem(
+[[nodiscard]] auto FindAlbumItem(
 		std::vector<SendingAlbum::Item> &items,
 		not_null<HistoryItem*> item) {
 	const auto result = ranges::find(
@@ -127,7 +131,7 @@ auto FindAlbumItem(
 	return result;
 }
 
-MTPInputSingleMedia PrepareAlbumItemMedia(
+[[nodiscard]] MTPInputSingleMedia PrepareAlbumItemMedia(
 		not_null<HistoryItem*> item,
 		const MTPInputMedia &media,
 		uint64 randomId) {
@@ -149,7 +153,7 @@ MTPInputSingleMedia PrepareAlbumItemMedia(
 		sentEntities);
 }
 
-std::vector<not_null<DocumentData*>> ExtractStickersFromScene(
+[[nodiscard]] std::vector<not_null<DocumentData*>> ExtractStickersFromScene(
 		not_null<const Ui::PreparedFileInformation::Image*> info) {
 	const auto allItems = info->modifications.paint->items();
 
@@ -162,6 +166,33 @@ std::vector<not_null<DocumentData*>> ExtractStickersFromScene(
 	}) | ranges::to_vector;
 }
 
+[[nodiscard]] QByteArray ComputePhotoJpegBytes(
+		QImage &full,
+		const QByteArray &bytes,
+		const QByteArray &format) {
+	if (!bytes.isEmpty()
+		&& (bytes.size()
+			<= full.width() * full.height() * kRecompressAfterBpp / 8)
+		&& (format == u"jpeg"_q)
+		&& Images::IsProgressiveJpeg(bytes)) {
+		return bytes;
+	}
+
+	// We have an example of dark .png image that when being sent without
+	// removing its color space is displayed fine on tdesktop, but with
+	// a light gray background on mobile apps.
+	full.setColorSpace(QColorSpace());
+	auto result = QByteArray();
+	QBuffer buffer(&result);
+	QImageWriter writer(&buffer, "JPEG");
+	writer.setQuality(87);
+	writer.setProgressiveScanWrite(true);
+	writer.write(full);
+	buffer.close();
+
+	return result;
+}
+
 } // namespace
 
 SendMediaPrepare::SendMediaPrepare(
@@ -663,15 +694,23 @@ bool FileLoadTask::CheckForImage(
 		return Images::Read({
 			.path = filepath,
 			.content = content,
+			.returnContent = true,
 		});
 	}();
-	return FillImageInformation(std::move(read.image), read.animated, result);
+	return FillImageInformation(
+		std::move(read.image),
+		read.animated,
+		result,
+		std::move(read.content),
+		std::move(read.format));
 }
 
 bool FileLoadTask::FillImageInformation(
 		QImage &&image,
 		bool animated,
-		std::unique_ptr<Ui::PreparedFileInformation> &result) {
+		std::unique_ptr<Ui::PreparedFileInformation> &result,
+		QByteArray content,
+		QByteArray format) {
 	Expects(result != nullptr);
 
 	if (image.isNull()) {
@@ -679,6 +718,8 @@ bool FileLoadTask::FillImageInformation(
 	}
 	auto media = Ui::PreparedFileInformation::Image();
 	media.data = std::move(image);
+	media.bytes = std::move(content);
+	media.format = std::move(format);
 	media.animated = animated;
 	result->media = media;
 	return true;
@@ -703,6 +744,8 @@ void FileLoadTask::process(Args &&args) {
 	auto isSticker = false;
 
 	auto fullimage = QImage();
+	auto fullimagebytes = QByteArray();
+	auto fullimageformat = QByteArray();
 	auto info = _filepath.isEmpty() ? QFileInfo() : QFileInfo(_filepath);
 	if (info.exists()) {
 		if (info.isDir()) {
@@ -724,8 +767,12 @@ void FileLoadTask::process(Args &&args) {
 		if (auto image = std::get_if<Ui::PreparedFileInformation::Image>(
 				&_information->media)) {
 			fullimage = base::take(image->data);
-			if (!Core::IsMimeSticker(filemime)) {
+			fullimagebytes = base::take(image->bytes);
+			fullimageformat = base::take(image->format);
+			if (!Core::IsMimeSticker(filemime)
+				&& fullimageformat != u"jpeg"_q) {
 				fullimage = Images::Opaque(std::move(fullimage));
+				fullimagebytes = fullimageformat = QByteArray();
 			}
 			isAnimation = image->animated;
 		}
@@ -739,12 +786,16 @@ void FileLoadTask::process(Args &&args) {
 				if (auto image = std::get_if<Ui::PreparedFileInformation::Image>(
 						&_information->media)) {
 					fullimage = base::take(image->data);
+					fullimagebytes = base::take(image->bytes);
+					fullimageformat = base::take(image->format);
 				}
 			}
 			const auto mimeType = Core::MimeTypeForData(_content);
 			filemime = mimeType.name();
-			if (!Core::IsMimeSticker(filemime)) {
+			if (!Core::IsMimeSticker(filemime)
+				&& fullimageformat != u"jpeg"_q) {
 				fullimage = Images::Opaque(std::move(fullimage));
+				fullimagebytes = fullimageformat = QByteArray();
 			}
 			if (filemime == "image/jpeg") {
 				filename = filedialogDefaultName(qsl("photo"), qsl(".jpg"), QString(), true);
@@ -764,6 +815,8 @@ void FileLoadTask::process(Args &&args) {
 			if (auto image = std::get_if<Ui::PreparedFileInformation::Image>(
 					&_information->media)) {
 				fullimage = base::take(image->data);
+				fullimagebytes = base::take(image->bytes);
+				fullimageformat = base::take(image->format);
 			}
 		}
 		if (!fullimage.isNull() && fullimage.width() > 0) {
@@ -786,6 +839,7 @@ void FileLoadTask::process(Args &&args) {
 				filesize = _content.size();
 			}
 			fullimage = Images::Opaque(std::move(fullimage));
+			fullimagebytes = fullimageformat = QByteArray();
 		}
 	}
 	_result->filesize = (int32)qMin(filesize, qint64(INT_MAX));
@@ -878,18 +932,14 @@ void FileLoadTask::process(Args &&args) {
 			} else if (filemime.startsWith(u"image/"_q)
 				&& _type != SendMediaType::File) {
 				auto medium = (w > 320 || h > 320) ? fullimage.scaled(320, 320, Qt::KeepAspectRatio, Qt::SmoothTransformation) : fullimage;
-				auto full = (w > 1280 || h > 1280) ? fullimage.scaled(1280, 1280, Qt::KeepAspectRatio, Qt::SmoothTransformation) : fullimage;
-				{
-					// We have an example of dark .png image that when being sent without
-					// removing its color space is displayed fine on tdesktop, but with
-					// a light gray background on mobile apps.
-					full.setColorSpace(QColorSpace());
-					QBuffer buffer(&filedata);
-					QImageWriter writer(&buffer, "JPEG");
-					writer.setQuality(87);
-					writer.setProgressiveScanWrite(true);
-					writer.write(full);
+
+				const auto downscaled = (w > 1280 || h > 1280);
+				auto full = downscaled ? fullimage.scaled(1280, 1280, Qt::KeepAspectRatio, Qt::SmoothTransformation) : fullimage;
+				if (downscaled) {
+					fullimagebytes = fullimageformat = QByteArray();
 				}
+				filedata = ComputePhotoJpegBytes(full, fullimagebytes, fullimageformat);
+
 				photoThumbs.emplace('m', PreparedPhotoThumb{ .image = medium });
 				photoSizes.push_back(MTP_photoSize(MTP_string("m"), MTP_int(medium.width()), MTP_int(medium.height()), MTP_int(0)));
 

Telegram/SourceFiles/storage/localimageloader.h

@@ -263,7 +263,9 @@ public:
 	static bool FillImageInformation(
 		QImage &&image,
 		bool animated,
-		std::unique_ptr<Ui::PreparedFileInformation> &result);
+		std::unique_ptr<Ui::PreparedFileInformation> &result,
+		QByteArray content = {},
+		QByteArray format = {});
 
 	FileLoadTask(
 		not_null<Main::Session*> session,

Telegram/SourceFiles/ui/chat/attach/attach_prepare.h

@@ -20,6 +20,8 @@ class SendFilesWay;
 struct PreparedFileInformation {
 	struct Image {
 		QImage data;
+		QByteArray bytes;
+		QByteArray format;
 		bool animated = false;
 		Editor::PhotoModifications modifications;
 	};

Telegram/lib_ui

@@ -1 +1 @@
-Subproject commit dd3cc5000e4f136ee198c5ace014640593e0aa2c
+Subproject commit 81e216f1cede22d30573233c36039716cc438b33