From 5bf746156688456c1594a7a87c7cf83c324af922 Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Tue, 3 Mar 2026 18:06:50 +0200
Subject: [PATCH] handlematrix: convert webp images to jpeg

---
 go.mod                        |  1 +
 go.sum                        |  2 ++
 pkg/connector/capabilities.go |  1 +
 pkg/connector/handlematrix.go | 38 ++++++++++++++++++++++++++++-------
 4 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/go.mod b/go.mod
index 499aa252..59837779 100644
--- a/go.mod
+++ b/go.mod
@@ -37,6 +37,7 @@ require (
 	go.uber.org/zap v1.27.1
 	golang.org/x/crypto v0.48.0
 	golang.org/x/exp v0.0.0-20260212183809-81e46e3db34a
+	golang.org/x/image v0.36.0
 	golang.org/x/net v0.50.0
 	golang.org/x/sync v0.19.0
 	golang.org/x/tools v0.42.0
diff --git a/go.sum b/go.sum
index fe3a3331..c5b3cf2d 100644
--- a/go.sum
+++ b/go.sum
@@ -156,6 +156,8 @@ golang.org/x/crypto v0.48.0 h1:/VRzVqiRSggnhY7gNRxPauEQ5Drw9haKdM0jqfcCFts=
 golang.org/x/crypto v0.48.0/go.mod h1:r0kV5h3qnFPlQnBSrULhlsRfryS2pmewsg+XfMgkVos=
 golang.org/x/exp v0.0.0-20260212183809-81e46e3db34a h1:ovFr6Z0MNmU7nH8VaX5xqw+05ST2uO1exVfZPVqRC5o=
 golang.org/x/exp v0.0.0-20260212183809-81e46e3db34a/go.mod h1:K79w1Vqn7PoiZn+TkNpx3BUWUQksGO3JcVX6qIjytmA=
+golang.org/x/image v0.36.0 h1:Iknbfm1afbgtwPTmHnS2gTM/6PPZfH+z2EFuOkSbqwc=
+golang.org/x/image v0.36.0/go.mod h1:YsWD2TyyGKiIX1kZlu9QfKIsQ4nAAK9bdgdrIsE7xy4=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
diff --git a/pkg/connector/capabilities.go b/pkg/connector/capabilities.go
index 7a1ec175..52f623c4 100644
--- a/pkg/connector/capabilities.go
+++ b/pkg/connector/capabilities.go
@@ -96,6 +96,7 @@ var fileCaps = event.FileFeatureMap{
 	event.MsgImage: {
 		MimeTypes: map[string]event.CapabilitySupportLevel{
 			"image/jpeg": event.CapLevelFullySupported,
+			"image/webp": event.CapLevelPartialSupport,
 			"image/png":  event.CapLevelPartialSupport,
 			"image/gif":  event.CapLevelPartialSupport,
 		},
diff --git a/pkg/connector/handlematrix.go b/pkg/connector/handlematrix.go
index f5bb7094..9ab229ce 100644
--- a/pkg/connector/handlematrix.go
+++ b/pkg/connector/handlematrix.go
@@ -23,8 +23,10 @@ import (
 	"errors"
 	"fmt"
 	"image"
+	"image/jpeg"
 	_ "image/jpeg"
 	_ "image/png"
+	"io"
 	"math"
 	"math/rand/v2"
 	"os"
@@ -39,6 +41,7 @@ import (
 	"go.mau.fi/util/variationselector"
 	"go.mau.fi/webp"
 	"golang.org/x/exp/maps"
+	_ "golang.org/x/image/webp"
 	"maunium.net/go/mautrix/bridgev2"
 	"maunium.net/go/mautrix/bridgev2/database"
 	"maunium.net/go/mautrix/bridgev2/networkid"
@@ -116,17 +119,17 @@ func (t *TelegramClient) transferMediaToTelegram(ctx context.Context, content *e
 	err := t.main.Bridge.Bot.DownloadMediaToFile(ctx, content.URL, content.File, false, func(f *os.File) (err error) {
 		uploadFilename := f.Name()
 		if sticker && content.Info != nil && (content.Info.MimeType == "image/png" || content.Info.MimeType == "image/jpeg") {
-			tempFile, err := os.CreateTemp("", "telegram-sticker-*")
+			tempFile, err := os.CreateTemp("", "telegram-sticker-*.webp")
 			if err != nil {
 				return err
 			}
 			defer func() {
-				tempFile.Close()
-				os.Remove(tempFile.Name())
+				_ = tempFile.Close()
+				_ = os.Remove(tempFile.Name())
 			}()
-			if image, _, err := image.Decode(f); err != nil {
+			if img, _, err := image.Decode(f); err != nil {
 				return fmt.Errorf("failed to decode sticker image: %w", err)
-			} else if err := webp.Encode(tempFile, image, nil); err != nil {
+			} else if err := webp.Encode(tempFile, img, nil); err != nil {
 				return fmt.Errorf("failed to encode sticker webp image: %w", err)
 			}
 			uploadFilename = tempFile.Name()
@@ -158,9 +161,30 @@ func (t *TelegramClient) transferMediaToTelegram(ctx context.Context, content *e
 				aspectRatio > 20 ||
 				cfg.Height+cfg.Width > 10000
 		}
+		if !forceDocument && !sticker && content.MsgType == event.MsgImage {
+			_, err = f.Seek(0, io.SeekStart)
+			if err != nil {
+				return err
+			}
+			tempFile, err := os.CreateTemp("", "telegram-nonsticker-*.jpeg")
+			if err != nil {
+				return err
+			}
+			defer func() {
+				_ = tempFile.Close()
+				_ = os.Remove(tempFile.Name())
+			}()
+			if img, _, err := image.Decode(f); err != nil {
+				return fmt.Errorf("failed to decode non-sticker webp image: %w", err)
+			} else if err := jpeg.Encode(tempFile, img, nil); err != nil {
+				return fmt.Errorf("failed to encode non-sticker jpeg image: %w", err)
+			}
+			uploadFilename = tempFile.Name()
+			filename += ".jpeg"
+			content.Info.MimeType = "image/jpeg"
+		}
 
-		uploader := uploader.NewUploader(t.client.API())
-		upload, err = uploader.FromPath(ctx, uploadFilename, filename)
+		upload, err = uploader.NewUploader(t.client.API()).FromPath(ctx, uploadFilename, filename)
 		return
 	})
 	if err != nil {