Convert .tgs with go libraries (and cgo) (telegram) (#1569)

This commit adds support for go/cgo tgs conversion when building with the -tags `cgo`
The default binaries are still "pure" go and uses the old way of converting.

* Move lottie_convert.py conversion code to its own file

* Add optional libtgsconverter

* Update vendor

* Apply suggestions from code review

* Update bridge/helper/libtgsconverter.go

Co-authored-by: Wim <wim@42.be>

9 files changed, 753 insertions, 0 deletions

diff --git a/vendor/github.com/Benau/tgsconverter/LICENSE b/vendor/github.com/Benau/tgsconverter/LICENSE
new file mode 100644
index 00000000..86fd0417
--- /dev/null
+++ b/vendor/github.com/Benau/tgsconverter/LICENSE
@@ -0,0 +1,24 @@
+The MIT License
+
+Copyright (c) 2021, (see AUTHORS)
+
+Permission is hereby granted, free of charge, to any person
+obtaining a copy of this software and associated documentation
+files (the "Software"), to deal in the Software without
+restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
diff --git a/vendor/github.com/Benau/tgsconverter/libtgsconverter/apng.go b/vendor/github.com/Benau/tgsconverter/libtgsconverter/apng.go
new file mode 100644
index 00000000..78541533
--- /dev/null
+++ b/vendor/github.com/Benau/tgsconverter/libtgsconverter/apng.go
@@ -0,0 +1,51 @@
+package libtgsconverter
+
+import "bytes"
+import "image"
+
+import "github.com/kettek/apng"
+import "github.com/av-elier/go-decimal-to-rational"
+
+type toapng struct {
+	apng apng.APNG
+	prev_frame *image.RGBA
+}
+
+func(to_apng *toapng) init(w uint, h uint, options ConverterOptions) {
+}
+
+func(to_apng *toapng) SupportsAnimation() bool {
+	return true
+}
+
+func (to_apng *toapng) AddFrame(image *image.RGBA, fps uint) error {
+	if to_apng.prev_frame != nil && sameImage(to_apng.prev_frame, image) {
+		var idx = len(to_apng.apng.Frames) - 1
+		var prev_fps = float64(to_apng.apng.Frames[idx].DelayNumerator) / float64(to_apng.apng.Frames[idx].DelayDenominator)
+		prev_fps += 1.0 / float64(fps)
+		rat := dectofrac.NewRatP(prev_fps, 0.001)
+		to_apng.apng.Frames[idx].DelayNumerator = uint16(rat.Num().Int64())
+		to_apng.apng.Frames[idx].DelayDenominator = uint16(rat.Denom().Int64())
+		return nil
+	}
+	f := apng.Frame{}
+	f.Image = image
+	f.DelayNumerator = 1
+	f.DelayDenominator = uint16(fps)
+	f.DisposeOp = apng.DISPOSE_OP_BACKGROUND
+	f.BlendOp = apng.BLEND_OP_SOURCE
+	f.IsDefault = false
+	to_apng.apng.Frames = append(to_apng.apng.Frames, f)
+	to_apng.prev_frame = image
+	return nil
+}
+
+func (to_apng *toapng) Result() []byte {
+	var data []byte
+	w := bytes.NewBuffer(data)
+	err := apng.Encode(w, to_apng.apng)
+	if err != nil {
+		return nil
+	}
+	return w.Bytes()
+}
diff --git a/vendor/github.com/Benau/tgsconverter/libtgsconverter/gif.go b/vendor/github.com/Benau/tgsconverter/libtgsconverter/gif.go
new file mode 100644
index 00000000..c4f5c5d9
--- /dev/null
+++ b/vendor/github.com/Benau/tgsconverter/libtgsconverter/gif.go
@@ -0,0 +1,81 @@
+package libtgsconverter
+
+import "bytes"
+
+import "image"
+import "image/color"
+import "image/gif"
+
+type togif struct {
+	gif gif.GIF
+	images []image.Image
+	prev_frame *image.RGBA
+}
+
+func(to_gif *togif) init(w uint, h uint, options ConverterOptions) {
+	to_gif.gif.Config.Width = int(w)
+	to_gif.gif.Config.Height = int(h)
+}
+
+func(to_gif *togif) SupportsAnimation() bool {
+	return true
+}
+
+func (to_gif *togif) AddFrame(image *image.RGBA, fps uint) error {
+	var fps_int = int(1.0 / float32(fps) * 100.)
+	if to_gif.prev_frame != nil && sameImage(to_gif.prev_frame, image) {
+		to_gif.gif.Delay[len(to_gif.gif.Delay) - 1] += fps_int
+		return nil
+	}
+	to_gif.gif.Image = append(to_gif.gif.Image, nil)
+	to_gif.gif.Delay = append(to_gif.gif.Delay, fps_int)
+	to_gif.gif.Disposal = append(to_gif.gif.Disposal, gif.DisposalBackground)
+	to_gif.images = append(to_gif.images, image)
+	to_gif.prev_frame = image
+	return nil
+}
+
+func (to_gif *togif) Result() []byte {
+	q := medianCutQuantizer{mode, nil, false}
+	p := q.quantizeMultiple(make([]color.Color, 0, 256), to_gif.images)
+	// Add transparent entry finally
+	var trans_idx uint8 = 0
+	if q.reserveTransparent {
+		trans_idx = uint8(len(p))
+	}
+	var id_map = make(map[uint32]uint8)
+	for i, img := range to_gif.images {
+		pi := image.NewPaletted(img.Bounds(), p)
+		for y := 0; y < img.Bounds().Dy(); y++ {
+			for x := 0; x < img.Bounds().Dx(); x++ {
+				c := img.At(x, y)
+				cr, cg, cb, ca := c.RGBA()
+				cid := (cr >> 8) << 16 | cg | (cb >> 8)
+				if q.reserveTransparent && ca == 0 {
+					pi.Pix[pi.PixOffset(x, y)] = trans_idx
+				} else if val, ok := id_map[cid]; ok {
+					pi.Pix[pi.PixOffset(x, y)] = val
+				} else {
+					val := uint8(p.Index(c))
+					pi.Pix[pi.PixOffset(x, y)] = val
+					id_map[cid] = val
+				}
+			}
+		}
+		to_gif.gif.Image[i] = pi
+	}
+	if q.reserveTransparent {
+		p = append(p, color.RGBA{0, 0, 0, 0})
+	}
+	for _, img := range to_gif.gif.Image {
+		img.Palette = p
+	}
+	to_gif.gif.Config.ColorModel = p
+	var data []byte
+	w := bytes.NewBuffer(data)
+	err := gif.EncodeAll(w, &to_gif.gif)
+	if err != nil {
+		return nil
+	}
+	return w.Bytes()
+}
diff --git a/vendor/github.com/Benau/tgsconverter/libtgsconverter/imagewriter.go b/vendor/github.com/Benau/tgsconverter/libtgsconverter/imagewriter.go
new file mode 100644
index 00000000..9549e337
--- /dev/null
+++ b/vendor/github.com/Benau/tgsconverter/libtgsconverter/imagewriter.go
@@ -0,0 +1,40 @@
+package libtgsconverter
+
+import "image"
+
+type imageWriter interface {
+	init(w uint, h uint, options ConverterOptions)
+	SupportsAnimation() bool
+	AddFrame(image *image.RGBA, fps uint) error
+	Result() []byte
+}
+
+func sameImage(a *image.RGBA, b *image.RGBA) bool {
+	if len(a.Pix) != len(b.Pix) {
+		return false
+	}
+	for i, v := range a.Pix {
+		if v != b.Pix[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func newImageWriter(extension string, w uint, h uint, options ConverterOptions) imageWriter {
+	var writer imageWriter
+	switch extension {
+	case "apng":
+		writer = &toapng{}
+	case "gif":
+		writer = &togif{}
+	case "png":
+		writer = &topng{}
+	case "webp":
+		writer = &towebp{}
+	default:
+		return nil
+	}
+	writer.init(w, h, options)
+	return writer
+}
diff --git a/vendor/github.com/Benau/tgsconverter/libtgsconverter/lib.go b/vendor/github.com/Benau/tgsconverter/libtgsconverter/lib.go
new file mode 100644
index 00000000..af6f8ab0
--- /dev/null
+++ b/vendor/github.com/Benau/tgsconverter/libtgsconverter/lib.go
@@ -0,0 +1,160 @@
+package libtgsconverter
+
+import "bytes"
+import "errors"
+import "compress/gzip"
+import "image"
+import "io/ioutil"
+
+import "github.com/Benau/go_rlottie"
+
+type ConverterOptions interface {
+	SetExtension(ext string)
+	SetFPS(fps uint)
+	SetScale(scale float32)
+	SetWebpQuality(webp_quality float32)
+	GetExtension() string
+	GetFPS() uint
+	GetScale() float32
+	GetWebpQuality() float32
+}
+
+type converter_options struct {
+	// apng, gif, png or webp
+	extension string
+	// Frame per second of output image (if you specify apng, gif or webp)
+	fps uint
+	// Scale of image result
+	scale float32
+	// Webp encoder quality (0 to 100)
+	webpQuality float32
+}
+
+func(opt *converter_options) SetExtension(ext string) {
+	opt.extension = ext
+}
+
+func(opt *converter_options) SetFPS(fps uint) {
+	opt.fps = fps
+}
+
+func(opt *converter_options) SetScale(scale float32) {
+	opt.scale = scale
+}
+
+func(opt *converter_options) SetWebpQuality(webp_quality float32) {
+	opt.webpQuality = webp_quality
+}
+
+func(opt *converter_options) GetExtension() string {
+	return opt.extension
+}
+
+func(opt *converter_options) GetFPS() uint {
+	return opt.fps
+}
+
+func(opt *converter_options) GetScale() float32 {
+	return opt.scale
+}
+
+func(opt *converter_options) GetWebpQuality() float32 {
+	return opt.webpQuality
+}
+
+func NewConverterOptions() ConverterOptions {
+	return &converter_options{"png", 30, 1.0, 75}
+}
+
+func imageFromBuffer(p []byte, w uint, h uint) *image.RGBA {
+	// rlottie use ARGB32_Premultiplied
+	for i := 0; i < len(p); i += 4 {
+		p[i + 0], p[i + 2] = p[i + 2], p[i + 0]
+	}
+	m := image.NewRGBA(image.Rect(0, 0, int(w), int(h)))
+	m.Pix = p
+	m.Stride = int(w) * 4
+	return m
+}
+
+var disabled_cache = false
+func ImportFromData(data []byte, options ConverterOptions) ([]byte, error) {
+	if !disabled_cache {
+		disabled_cache = true
+		go_rlottie.LottieConfigureModelCacheSize(0)
+	}
+	z, err := gzip.NewReader(bytes.NewReader(data))
+	if err != nil {
+		return nil, errors.New("Failed to create gzip reader:" + err.Error())
+	}
+	uncompressed, err := ioutil.ReadAll(z)
+	if err != nil {
+		return nil, errors.New("Failed to read gzip archive")
+	}
+	z.Close()
+
+	animation := go_rlottie.LottieAnimationFromData(string(uncompressed[:]), "", "")
+	if animation == nil {
+		return nil, errors.New("Failed to import lottie animation data")
+	}
+
+	w, h := go_rlottie.LottieAnimationGetSize(animation)
+	w = uint(float32(w) * options.GetScale())
+	h = uint(float32(h) * options.GetScale())
+
+	frame_rate := go_rlottie.LottieAnimationGetFramerate(animation)
+	frame_count := go_rlottie.LottieAnimationGetTotalframe(animation)
+	duration := float32(frame_count) / float32(frame_rate)
+	var desired_framerate = float32(options.GetFPS())
+	// Most (Gif) player doesn't support ~60fps (found in most tgs)
+	if desired_framerate > 50. {
+		desired_framerate = 50.
+	}
+	step := 1.0 / desired_framerate
+
+	writer := newImageWriter(options.GetExtension(), w, h, options)
+	if writer == nil {
+		return nil, errors.New("Failed create imagewriter")
+	}
+
+	var i float32
+	for i = 0.; i < duration; i += step {
+		frame := go_rlottie.LottieAnimationGetFrameAtPos(animation, i / duration)
+		buf := make([]byte, w * h * 4)
+		go_rlottie.LottieAnimationRender(animation, frame, buf, w, h, w * 4)
+		m := imageFromBuffer(buf, w, h)
+		err := writer.AddFrame(m, uint(desired_framerate))
+		if err != nil {
+			return nil, errors.New("Failed to add frame:" + err.Error())
+		}
+		if !writer.SupportsAnimation() {
+			break
+		}
+	}
+	go_rlottie.LottieAnimationDestroy(animation)
+	return writer.Result(), nil
+}
+
+func ImportFromFile(path string, options ConverterOptions) ([]byte, error) {
+	tgs, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, errors.New("Error when opening file:" + err.Error())
+	}
+	return ImportFromData(tgs, options)
+}
+
+func SupportsExtension(extension string) (bool) {
+	switch extension {
+	case "apng":
+		fallthrough
+	case "gif":
+		fallthrough
+	case "png":
+		fallthrough
+	case "webp":
+		return true
+	default:
+		return false
+	}
+	return false
+}
diff --git a/vendor/github.com/Benau/tgsconverter/libtgsconverter/png.go b/vendor/github.com/Benau/tgsconverter/libtgsconverter/png.go
new file mode 100644
index 00000000..cf492ea4
--- /dev/null
+++ b/vendor/github.com/Benau/tgsconverter/libtgsconverter/png.go
@@ -0,0 +1,30 @@
+package libtgsconverter
+
+import "bytes"
+import "image"
+import "image/png"
+
+type topng struct {
+	result []byte
+}
+
+func(to_png *topng) init(w uint, h uint, options ConverterOptions) {
+}
+
+func(to_png *topng) SupportsAnimation() bool {
+	return false
+}
+
+func (to_png *topng) AddFrame(image *image.RGBA, fps uint) error {
+	var data []byte
+	w := bytes.NewBuffer(data)
+	if err := png.Encode(w, image); err != nil {
+		return err
+	}
+	to_png.result = w.Bytes()
+	return nil
+}
+
+func (to_png *topng) Result() []byte {
+	return to_png.result
+}
diff --git a/vendor/github.com/Benau/tgsconverter/libtgsconverter/quantize_bucket.go b/vendor/github.com/Benau/tgsconverter/libtgsconverter/quantize_bucket.go
new file mode 100644
index 00000000..1f00c685
--- /dev/null
+++ b/vendor/github.com/Benau/tgsconverter/libtgsconverter/quantize_bucket.go
@@ -0,0 +1,119 @@
+package libtgsconverter
+
+import "image/color"
+
+type colorAxis uint8
+
+// Color axis constants
+const (
+	red colorAxis = iota
+	green
+	blue
+)
+
+type colorPriority struct {
+	p uint32
+	color.RGBA
+}
+
+func (c colorPriority) axis(span colorAxis) uint8 {
+	switch span {
+	case red:
+		return c.R
+	case green:
+		return c.G
+	default:
+		return c.B
+	}
+}
+
+type colorBucket []colorPriority
+
+func (cb colorBucket) partition() (colorBucket, colorBucket) {
+	mean, span := cb.span()
+	left, right := 0, len(cb)-1
+	for left < right {
+		cb[left], cb[right] = cb[right], cb[left]
+		for cb[left].axis(span) < mean && left < right {
+			left++
+		}
+		for cb[right].axis(span) >= mean && left < right {
+			right--
+		}
+	}
+	if left == 0 {
+		return cb[:1], cb[1:]
+	}
+	if left == len(cb)-1 {
+		return cb[:len(cb)-1], cb[len(cb)-1:]
+	}
+	return cb[:left], cb[left:]
+}
+
+func (cb colorBucket) mean() color.RGBA {
+	var r, g, b uint64
+	var p uint64
+	for _, c := range cb {
+		p += uint64(c.p)
+		r += uint64(c.R) * uint64(c.p)
+		g += uint64(c.G) * uint64(c.p)
+		b += uint64(c.B) * uint64(c.p)
+	}
+	return color.RGBA{uint8(r / p), uint8(g / p), uint8(b / p), 255}
+}
+
+type constraint struct {
+	min  uint8
+	max  uint8
+	vals [256]uint64
+}
+
+func (c *constraint) update(index uint8, p uint32) {
+	if index < c.min {
+		c.min = index
+	}
+	if index > c.max {
+		c.max = index
+	}
+	c.vals[index] += uint64(p)
+}
+
+func (c *constraint) span() uint8 {
+	return c.max - c.min
+}
+
+func (cb colorBucket) span() (uint8, colorAxis) {
+	var R, G, B constraint
+	R.min = 255
+	G.min = 255
+	B.min = 255
+	var p uint64
+	for _, c := range cb {
+		R.update(c.R, c.p)
+		G.update(c.G, c.p)
+		B.update(c.B, c.p)
+		p += uint64(c.p)
+	}
+	var toCount *constraint
+	var span colorAxis
+	if R.span() > G.span() && R.span() > B.span() {
+		span = red
+		toCount = &R
+	} else if G.span() > B.span() {
+		span = green
+		toCount = &G
+	} else {
+		span = blue
+		toCount = &B
+	}
+	var counted uint64
+	var i int
+	var c uint64
+	for i, c = range toCount.vals {
+		if counted > p/2 || counted+c == p {
+			break
+		}
+		counted += c
+	}
+	return uint8(i), span
+}
diff --git a/vendor/github.com/Benau/tgsconverter/libtgsconverter/quantize_mediancut.go b/vendor/github.com/Benau/tgsconverter/libtgsconverter/quantize_mediancut.go
new file mode 100644
index 00000000..850708b9
--- /dev/null
+++ b/vendor/github.com/Benau/tgsconverter/libtgsconverter/quantize_mediancut.go
@@ -0,0 +1,209 @@
+package libtgsconverter
+
+import (
+	"image"
+	"image/color"
+	"sync"
+)
+
+type bucketPool struct {
+	sync.Pool
+	maxCap int
+	m      sync.Mutex
+}
+
+func (p *bucketPool) getBucket(c int) colorBucket {
+	p.m.Lock()
+	if p.maxCap > c {
+		p.maxCap = p.maxCap * 99 / 100
+	}
+	if p.maxCap < c {
+		p.maxCap = c
+	}
+	maxCap := p.maxCap
+	p.m.Unlock()
+	val := p.Pool.Get()
+	if val == nil || cap(val.(colorBucket)) < c {
+		return make(colorBucket, maxCap)[0:c]
+	}
+	slice := val.(colorBucket)
+	slice = slice[0:c]
+	for i := range slice {
+		slice[i] = colorPriority{}
+	}
+	return slice
+}
+
+var bpool bucketPool
+
+// aggregationType specifies the type of aggregation to be done
+type aggregationType uint8
+
+const (
+	// Mode - pick the highest priority value
+	mode aggregationType = iota
+	// Mean - weighted average all values
+	mean
+)
+
+// medianCutQuantizer implements the go draw.Quantizer interface using the Median Cut method
+type medianCutQuantizer struct {
+	// The type of aggregation to be used to find final colors
+	aggregation aggregationType
+	// The weighting function to use on each pixel
+	weighting func(image.Image, int, int) uint32
+	// Whether need to add a transparent entry after conversion
+	reserveTransparent bool
+}
+
+//bucketize takes a bucket and performs median cut on it to obtain the target number of grouped buckets
+func bucketize(colors colorBucket, num int) (buckets []colorBucket) {
+	if len(colors) == 0 || num == 0 {
+		return nil
+	}
+	bucket := colors
+	buckets = make([]colorBucket, 1, num*2)
+	buckets[0] = bucket
+
+	for len(buckets) < num && len(buckets) < len(colors) { // Limit to palette capacity or number of colors
+		bucket, buckets = buckets[0], buckets[1:]
+		if len(bucket) < 2 {
+			buckets = append(buckets, bucket)
+			continue
+		} else if len(bucket) == 2 {
+			buckets = append(buckets, bucket[:1], bucket[1:])
+			continue
+		}
+
+		left, right := bucket.partition()
+		buckets = append(buckets, left, right)
+	}
+	return
+}
+
+// palettize finds a single color to represent a set of color buckets
+func (q* medianCutQuantizer) palettize(p color.Palette, buckets []colorBucket) color.Palette {
+	for _, bucket := range buckets {
+		switch q.aggregation {
+		case mean:
+			mean := bucket.mean()
+			p = append(p, mean)
+		case mode:
+			var best colorPriority
+			for _, c := range bucket {
+				if c.p > best.p {
+					best = c
+				}
+			}
+			p = append(p, best.RGBA)
+		}
+	}
+	return p
+}
+
+// quantizeSlice expands the provided bucket and then palettizes the result
+func (q* medianCutQuantizer) quantizeSlice(p color.Palette, colors []colorPriority) color.Palette {
+	numColors := cap(p) - len(p)
+	reserveTransparent := q.reserveTransparent
+	if reserveTransparent {
+		numColors--
+	}
+	buckets := bucketize(colors, numColors)
+	p = q.palettize(p, buckets)
+	return p
+}
+
+func colorAt(m image.Image, x int, y int) color.RGBA {
+	switch i := m.(type) {
+	case *image.YCbCr:
+		yi := i.YOffset(x, y)
+		ci := i.COffset(x, y)
+		c := color.YCbCr{
+			i.Y[yi],
+			i.Cb[ci],
+			i.Cr[ci],
+		}
+		return color.RGBA{c.Y, c.Cb, c.Cr, 255}
+	case *image.RGBA:
+		ci := i.PixOffset(x, y)
+		return color.RGBA{i.Pix[ci+0], i.Pix[ci+1], i.Pix[ci+2], i.Pix[ci+3]}
+	default:
+		return color.RGBAModel.Convert(i.At(x, y)).(color.RGBA)
+	}
+}
+
+// buildBucketMultiple creates a prioritized color slice with all the colors in
+// the images.
+func (q* medianCutQuantizer) buildBucketMultiple(ms []image.Image) (bucket colorBucket) {
+	if len(ms) < 1 {
+		return colorBucket{}
+	}
+
+	bounds := ms[0].Bounds()
+	size := (bounds.Max.X - bounds.Min.X) * (bounds.Max.Y - bounds.Min.Y) * 2
+	sparseBucket := bpool.getBucket(size)
+
+	for _, m := range ms {
+		for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
+			for x := bounds.Min.X; x < bounds.Max.X; x++ {
+				priority := uint32(1)
+				if q.weighting != nil {
+					priority = q.weighting(m, x, y)
+				}
+				c := colorAt(m, x, y)
+				if c.A == 0 {
+					if !q.reserveTransparent {
+						q.reserveTransparent = true
+					}
+					continue
+				}
+				if priority != 0 {
+					index := int(c.R)<<16 | int(c.G)<<8 | int(c.B)
+					for i := 1; ; i++ {
+						p := &sparseBucket[index%size]
+						if p.p == 0 || p.RGBA == c {
+							*p = colorPriority{p.p + priority, c}
+							break
+						}
+						index += 1 + i
+					}
+				}
+			}
+		}
+	}
+
+	bucket = sparseBucket[:0]
+	switch ms[0].(type) {
+	case *image.YCbCr:
+		for _, p := range sparseBucket {
+			if p.p != 0 {
+				r, g, b := color.YCbCrToRGB(p.R, p.G, p.B)
+				bucket = append(bucket, colorPriority{p.p, color.RGBA{r, g, b, p.A}})
+			}
+		}
+	default:
+		for _, p := range sparseBucket {
+			if p.p != 0 {
+				bucket = append(bucket, p)
+			}
+		}
+	}
+	return
+}
+
+// Quantize quantizes an image to a palette and returns the palette
+func (q* medianCutQuantizer) quantize(p color.Palette, m image.Image) color.Palette {
+	// Package quantize offers an implementation of the draw.Quantize interface using an optimized Median Cut method,
+	// including advanced functionality for fine-grained control of color priority
+	bucket := q.buildBucketMultiple([]image.Image{m})
+	defer bpool.Put(bucket)
+	return q.quantizeSlice(p, bucket)
+}
+
+// QuantizeMultiple quantizes several images at once to a palette and returns
+// the palette
+func (q* medianCutQuantizer) quantizeMultiple(p color.Palette, m []image.Image) color.Palette {
+	bucket := q.buildBucketMultiple(m)
+	defer bpool.Put(bucket)
+	return q.quantizeSlice(p, bucket)
+}
diff --git a/vendor/github.com/Benau/tgsconverter/libtgsconverter/webp.go b/vendor/github.com/Benau/tgsconverter/libtgsconverter/webp.go
new file mode 100644
index 00000000..60e9887c
--- /dev/null
+++ b/vendor/github.com/Benau/tgsconverter/libtgsconverter/webp.go
@@ -0,0 +1,39 @@
+package libtgsconverter
+
+import "bytes"
+import "image"
+
+import "github.com/sizeofint/webpanimation"
+
+type towebp struct {
+	timestamp int
+	webpanim *webpanimation.WebpAnimation
+	config webpanimation.WebPConfig
+}
+
+func(to_webp *towebp) init(w uint, h uint, options ConverterOptions) {
+	to_webp.timestamp = 0
+	to_webp.webpanim = webpanimation.NewWebpAnimation(int(w), int(h), 0)
+	to_webp.config = webpanimation.NewWebpConfig()
+	to_webp.config.SetQuality(options.GetWebpQuality())
+}
+
+func(to_webp *towebp) SupportsAnimation() bool {
+	return true
+}
+
+func (to_webp *towebp) AddFrame(image *image.RGBA, fps uint) error {
+	err := to_webp.webpanim.AddFrame(image, to_webp.timestamp, to_webp.config)
+	to_webp.timestamp += int((1.0 / float32(fps)) * 1000.)
+	return err
+}
+
+func (to_webp *towebp) Result() []byte {
+	var buf bytes.Buffer
+	err := to_webp.webpanim.Encode(&buf)
+	if err != nil {
+		return nil
+	}
+	to_webp.webpanim.ReleaseMemory()
+	return buf.Bytes()
+}