From fe73025481035de4d26412ed206f4ce3f66691b9 Mon Sep 17 00:00:00 2001 From: Ben Wiederhake Date: Fri, 17 Jul 2020 21:51:20 +0200 Subject: [PATCH] Support Telegram animated stickers (tgs) format MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This is half a fix for #874 This patch introduces two new config flags: - MediaConvertTgsToWebP - MediaConvertTgsToPNG These need to be treated independently from the existing MediaConvertWebPToPNG flag because Tgs→WebP results in an *animated* WebP, and the WebP→PNG converter can't handle animated WebP files yet. Furthermore, some platforms (like discord) don't even support animated WebP files, so the user may want to fall back to static PNGs (not APNGs). The final reason why this is only half a fix is that this introduces an external dependency, namely lottie, to be installed like this: $ pip3 install lottie cairosvg This patch works by writing the tgs to a temporary file in /tmp, calling lottie to convert it (this conversion may take several seconds!), and then deleting the temporary file. The temporary file is absolutely necessary, as lottie refuses to work on non-seekable files. If anyone comes up with a reasonable use case where /tmp is unavailable, I can add yet another config option for that, if desired. I will propose new text for the Wiki in the PR for this patch. (Should be #1173 or so.) --- bridge/config/config.go | 1 + bridge/helper/helper.go | 51 ++++++++++++++++++++++++++++++++++- bridge/telegram/handlers.go | 54 +++++++++++++++++++++++++++++++------ bridge/telegram/telegram.go | 11 ++++++++ 4 files changed, 108 insertions(+), 9 deletions(-) diff --git a/bridge/config/config.go b/bridge/config/config.go index 6e99066c3a..f34da511b2 100644 --- a/bridge/config/config.go +++ b/bridge/config/config.go @@ -100,6 +100,7 @@ type Protocol struct { MediaDownloadSize int // all protocols MediaServerDownload string MediaServerUpload string + MediaConvertTgs string // telegram MediaConvertWebPToPNG bool // telegram MessageDelay int // IRC, time in millisecond to wait between messages MessageFormat string // telegram diff --git a/bridge/helper/helper.go b/bridge/helper/helper.go index 412447661a..9a72b025f4 100644 --- a/bridge/helper/helper.go +++ b/bridge/helper/helper.go @@ -5,7 +5,10 @@ import ( "fmt" "image/png" "io" + "io/ioutil" "net/http" + "os" + "os/exec" "regexp" "strings" "time" @@ -192,7 +195,7 @@ func ParseMarkdown(input string) string { return res } -// ConvertWebPToPNG convert input data (which should be WebP format to PNG format) +// ConvertWebPToPNG converts input data (which should be WebP format) to PNG format func ConvertWebPToPNG(data *[]byte) error { r := bytes.NewReader(*data) m, err := webp.Decode(r) @@ -207,3 +210,49 @@ func ConvertWebPToPNG(data *[]byte) error { *data = w.Bytes() return nil } + +// CanConvertTgsToX Checks whether the external command necessary for ConvertTgsToX works. +func CanConvertTgsToX() error { + // We depend on the fact that `lottie_convert.py --help` has exit status 0. + // Hyrum's Law predicted this, and Murphy's Law predicts that this will break eventually. + // However, there is no alternative like `lottie_convert.py --is-properly-installed` + cmd := exec.Command("lottie_convert.py", "--help") + return cmd.Wait() +} + +// ConvertTgsToWebP convert input data (which should be tgs format) to WebP format +// This relies on an external command, which is ugly, but works. +func ConvertTgsToX(data *[]byte, outputFormat string, logger *logrus.Entry) error { + // lottie can't handle input from a pipe, so write to a temporary file: + tmpFile, err := ioutil.TempFile(os.TempDir(), "matterbridge-lottie-*.tgs") + if err != nil { + return err + } + tmpFileName := tmpFile.Name() + defer func() { + if removeErr := os.Remove(tmpFileName); removeErr != nil { + logger.Errorf("Could not delete temporary file %s: %v", tmpFileName, removeErr) + } + }() + + if _, writeErr := tmpFile.Write(*data); writeErr != nil { + return writeErr + } + // Must close before calling lottie to avoid data races: + if closeErr := tmpFile.Close(); closeErr != nil { + return closeErr + } + + // Call lottie to transform: + cmd := exec.Command("lottie_convert.py", "--input-format", "lottie", "--output-format", outputFormat, tmpFileName, "/dev/stdout") + cmd.Stderr = nil + // NB: lottie writes progress into to stderr in all cases. + stdout, stderr := cmd.Output() + if stderr != nil { + // 'stderr' already contains some parts of Stderr, because it was set to 'nil'. + return stderr + } + + *data = stdout + return nil +} diff --git a/bridge/telegram/handlers.go b/bridge/telegram/handlers.go index 5c60f74be9..de317b1bc9 100644 --- a/bridge/telegram/handlers.go +++ b/bridge/telegram/handlers.go @@ -217,6 +217,46 @@ func (b *Btelegram) handleDownloadAvatar(userid int, channel string) { } } +func (b *Btelegram) maybeConvertTgs(name *string, data *[]byte) { + var format string + switch b.GetString("MediaConvertTgs") { + case "webp": + b.Log.Debugf("Tgs to WebP conversion enabled, converting %v", name) + format = "webp" + case "png": + // The WebP to PNG converter can't handle animated webp files yet, + // and I'm not going to write a path for x/image/webp. + // The error message would be: + // conversion failed: webp: non-Alpha VP8X is not implemented + // So instead, we tell lottie to directly go to PNG. + b.Log.Debugf("Tgs to PNG conversion enabled, converting %v", name) + format = "png" + default: + // Otherwise, no conversion was requested. Trying to run the usual webp + // converter would fail, because '.tgs.webp' is actually a gzipped JSON + // file, and has nothing to do with WebP. + return + } + err := helper.ConvertTgsToX(data, format, b.Log) + if err != nil { + b.Log.Errorf("conversion failed: %v", err) + } else { + *name = strings.Replace(*name, "tgs.webp", format, 1) + } +} + +func (b *Btelegram) maybeConvertWebp(name *string, data *[]byte) { + if b.GetBool("MediaConvertWebPToPNG") { + b.Log.Debugf("WebP to PNG conversion enabled, converting %v", name) + err := helper.ConvertWebPToPNG(data) + if err != nil { + b.Log.Errorf("conversion failed: %v", err) + } else { + *name = strings.Replace(*name, ".webp", ".png", 1) + } + } +} + // handleDownloadFile handles file download func (b *Btelegram) handleDownload(rmsg *config.Message, message *tgbotapi.Message) error { size := 0 @@ -264,15 +304,13 @@ func (b *Btelegram) handleDownload(rmsg *config.Message, message *tgbotapi.Messa if err != nil { return err } - if strings.HasSuffix(name, ".webp") && b.GetBool("MediaConvertWebPToPNG") { - b.Log.Debugf("WebP to PNG conversion enabled, converting %s", name) - err := helper.ConvertWebPToPNG(data) - if err != nil { - b.Log.Errorf("conversion failed: %s", err) - } else { - name = strings.Replace(name, ".webp", ".png", 1) - } + + if strings.HasSuffix(name, ".tgs.webp") { + b.maybeConvertTgs(&name, data) + } else if strings.HasSuffix(name, ".webp") { + b.maybeConvertWebp(&name, data) } + helper.HandleDownloadData(b.Log, rmsg, name, message.Caption, "", data, b.General) return nil } diff --git a/bridge/telegram/telegram.go b/bridge/telegram/telegram.go index 29f2f2910b..8fe348c81f 100644 --- a/bridge/telegram/telegram.go +++ b/bridge/telegram/telegram.go @@ -2,6 +2,7 @@ package btelegram import ( "html" + "log" "strconv" "strings" @@ -25,6 +26,16 @@ type Btelegram struct { } func New(cfg *bridge.Config) bridge.Bridger { + tgsConvertFormat := cfg.GetString("MediaConvertTgs") + if tgsConvertFormat != "" { + err := helper.CanConvertTgsToX() + if err != nil { + log.Fatalf("Telegram bridge configured to convert .tgs files to '%s', but lottie does not appear to work:\n%v", tgsConvertFormat, err) + } + if tgsConvertFormat != "png" && tgsConvertFormat != "webp" { + log.Fatalf("Telegram bridge configured to convert .tgs files to '%s', but only 'png' and 'webp' are supported.", tgsConvertFormat) + } + } return &Btelegram{Config: cfg, avatarMap: make(map[string]string)} }