From b2af76e7dc90317369c767a686d87937aff54a20 Mon Sep 17 00:00:00 2001 From: Ben Wiederhake Date: Sun, 23 Aug 2020 22:34:28 +0200 Subject: Support Telegram animated stickers (tgs) format (#1173) 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 a new config flag: - MediaConvertTgs 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. Telegram will bail out if the option is configured but lottie isn't found. --- bridge/config/config.go | 1 + bridge/helper/helper.go | 51 +++++++++++++++++++++++++++++++++++++++++- bridge/telegram/handlers.go | 54 ++++++++++++++++++++++++++++++++++++++------- bridge/telegram/telegram.go | 13 +++++++++++ 4 files changed, 110 insertions(+), 9 deletions(-) (limited to 'bridge') diff --git a/bridge/config/config.go b/bridge/config/config.go index 6e99066c..f34da511 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 41244766..2b449e14 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.Run() +} + +// 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 5c60f74b..ee087524 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 FormatWebp: + b.Log.Debugf("Tgs to WebP conversion enabled, converting %v", name) + format = FormatWebp + case FormatPng: + // 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 = FormatPng + 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 29f2f291..f1c7168c 100644 --- a/bridge/telegram/telegram.go +++ b/bridge/telegram/telegram.go @@ -2,6 +2,7 @@ package btelegram import ( "html" + "log" "strconv" "strings" @@ -16,6 +17,8 @@ const ( HTMLFormat = "HTML" HTMLNick = "htmlnick" MarkdownV2 = "MarkdownV2" + FormatPng = "png" + FormatWebp = "webp" ) type Btelegram struct { @@ -25,6 +28,16 @@ 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 != FormatPng && tgsConvertFormat != FormatWebp { + log.Fatalf("Telegram bridge configured to convert .tgs files to '%s', but only '%s' and '%s' are supported.", FormatPng, FormatWebp, tgsConvertFormat) + } + } return &Btelegram{Config: cfg, avatarMap: make(map[string]string)} } -- cgit v1.2.3