mirror of
https://github.com/cwinfo/matterbridge.git
synced 2025-07-06 20:04:04 +00:00
Add MediaConvertWebPToPNG option (telegram). (#741)
* Add MediaConvertWebPToPNG option (telegram). When enabled matterbridge will convert .webp files to .png files before uploading them to the mediaserver of the other bridges. Fixes #398
This commit is contained in:
403
vendor/golang.org/x/image/vp8/decode.go
generated
vendored
Normal file
403
vendor/golang.org/x/image/vp8/decode.go
generated
vendored
Normal file
@ -0,0 +1,403 @@
|
||||
// Copyright 2011 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
// Package vp8 implements a decoder for the VP8 lossy image format.
|
||||
//
|
||||
// The VP8 specification is RFC 6386.
|
||||
package vp8 // import "golang.org/x/image/vp8"
|
||||
|
||||
// This file implements the top-level decoding algorithm.
|
||||
|
||||
import (
|
||||
"errors"
|
||||
"image"
|
||||
"io"
|
||||
)
|
||||
|
||||
// limitReader wraps an io.Reader to read at most n bytes from it.
|
||||
type limitReader struct {
|
||||
r io.Reader
|
||||
n int
|
||||
}
|
||||
|
||||
// ReadFull reads exactly len(p) bytes into p.
|
||||
func (r *limitReader) ReadFull(p []byte) error {
|
||||
if len(p) > r.n {
|
||||
return io.ErrUnexpectedEOF
|
||||
}
|
||||
n, err := io.ReadFull(r.r, p)
|
||||
r.n -= n
|
||||
return err
|
||||
}
|
||||
|
||||
// FrameHeader is a frame header, as specified in section 9.1.
|
||||
type FrameHeader struct {
|
||||
KeyFrame bool
|
||||
VersionNumber uint8
|
||||
ShowFrame bool
|
||||
FirstPartitionLen uint32
|
||||
Width int
|
||||
Height int
|
||||
XScale uint8
|
||||
YScale uint8
|
||||
}
|
||||
|
||||
const (
|
||||
nSegment = 4
|
||||
nSegmentProb = 3
|
||||
)
|
||||
|
||||
// segmentHeader holds segment-related header information.
|
||||
type segmentHeader struct {
|
||||
useSegment bool
|
||||
updateMap bool
|
||||
relativeDelta bool
|
||||
quantizer [nSegment]int8
|
||||
filterStrength [nSegment]int8
|
||||
prob [nSegmentProb]uint8
|
||||
}
|
||||
|
||||
const (
|
||||
nRefLFDelta = 4
|
||||
nModeLFDelta = 4
|
||||
)
|
||||
|
||||
// filterHeader holds filter-related header information.
|
||||
type filterHeader struct {
|
||||
simple bool
|
||||
level int8
|
||||
sharpness uint8
|
||||
useLFDelta bool
|
||||
refLFDelta [nRefLFDelta]int8
|
||||
modeLFDelta [nModeLFDelta]int8
|
||||
perSegmentLevel [nSegment]int8
|
||||
}
|
||||
|
||||
// mb is the per-macroblock decode state. A decoder maintains mbw+1 of these
|
||||
// as it is decoding macroblocks left-to-right and top-to-bottom: mbw for the
|
||||
// macroblocks in the row above, and one for the macroblock to the left.
|
||||
type mb struct {
|
||||
// pred is the predictor mode for the 4 bottom or right 4x4 luma regions.
|
||||
pred [4]uint8
|
||||
// nzMask is a mask of 8 bits: 4 for the bottom or right 4x4 luma regions,
|
||||
// and 2 + 2 for the bottom or right 4x4 chroma regions. A 1 bit indicates
|
||||
// that region has non-zero coefficients.
|
||||
nzMask uint8
|
||||
// nzY16 is a 0/1 value that is 1 if the macroblock used Y16 prediction and
|
||||
// had non-zero coefficients.
|
||||
nzY16 uint8
|
||||
}
|
||||
|
||||
// Decoder decodes VP8 bitstreams into frames. Decoding one frame consists of
|
||||
// calling Init, DecodeFrameHeader and then DecodeFrame in that order.
|
||||
// A Decoder can be re-used to decode multiple frames.
|
||||
type Decoder struct {
|
||||
// r is the input bitsream.
|
||||
r limitReader
|
||||
// scratch is a scratch buffer.
|
||||
scratch [8]byte
|
||||
// img is the YCbCr image to decode into.
|
||||
img *image.YCbCr
|
||||
// mbw and mbh are the number of 16x16 macroblocks wide and high the image is.
|
||||
mbw, mbh int
|
||||
// frameHeader is the frame header. When decoding multiple frames,
|
||||
// frames that aren't key frames will inherit the Width, Height,
|
||||
// XScale and YScale of the most recent key frame.
|
||||
frameHeader FrameHeader
|
||||
// Other headers.
|
||||
segmentHeader segmentHeader
|
||||
filterHeader filterHeader
|
||||
// The image data is divided into a number of independent partitions.
|
||||
// There is 1 "first partition" and between 1 and 8 "other partitions"
|
||||
// for coefficient data.
|
||||
fp partition
|
||||
op [8]partition
|
||||
nOP int
|
||||
// Quantization factors.
|
||||
quant [nSegment]quant
|
||||
// DCT/WHT coefficient decoding probabilities.
|
||||
tokenProb [nPlane][nBand][nContext][nProb]uint8
|
||||
useSkipProb bool
|
||||
skipProb uint8
|
||||
// Loop filter parameters.
|
||||
filterParams [nSegment][2]filterParam
|
||||
perMBFilterParams []filterParam
|
||||
|
||||
// The eight fields below relate to the current macroblock being decoded.
|
||||
//
|
||||
// Segment-based adjustments.
|
||||
segment int
|
||||
// Per-macroblock state for the macroblock immediately left of and those
|
||||
// macroblocks immediately above the current macroblock.
|
||||
leftMB mb
|
||||
upMB []mb
|
||||
// Bitmasks for which 4x4 regions of coeff contain non-zero coefficients.
|
||||
nzDCMask, nzACMask uint32
|
||||
// Predictor modes.
|
||||
usePredY16 bool // The libwebp C code calls this !is_i4x4_.
|
||||
predY16 uint8
|
||||
predC8 uint8
|
||||
predY4 [4][4]uint8
|
||||
|
||||
// The two fields below form a workspace for reconstructing a macroblock.
|
||||
// Their specific sizes are documented in reconstruct.go.
|
||||
coeff [1*16*16 + 2*8*8 + 1*4*4]int16
|
||||
ybr [1 + 16 + 1 + 8][32]uint8
|
||||
}
|
||||
|
||||
// NewDecoder returns a new Decoder.
|
||||
func NewDecoder() *Decoder {
|
||||
return &Decoder{}
|
||||
}
|
||||
|
||||
// Init initializes the decoder to read at most n bytes from r.
|
||||
func (d *Decoder) Init(r io.Reader, n int) {
|
||||
d.r = limitReader{r, n}
|
||||
}
|
||||
|
||||
// DecodeFrameHeader decodes the frame header.
|
||||
func (d *Decoder) DecodeFrameHeader() (fh FrameHeader, err error) {
|
||||
// All frame headers are at least 3 bytes long.
|
||||
b := d.scratch[:3]
|
||||
if err = d.r.ReadFull(b); err != nil {
|
||||
return
|
||||
}
|
||||
d.frameHeader.KeyFrame = (b[0] & 1) == 0
|
||||
d.frameHeader.VersionNumber = (b[0] >> 1) & 7
|
||||
d.frameHeader.ShowFrame = (b[0]>>4)&1 == 1
|
||||
d.frameHeader.FirstPartitionLen = uint32(b[0])>>5 | uint32(b[1])<<3 | uint32(b[2])<<11
|
||||
if !d.frameHeader.KeyFrame {
|
||||
return d.frameHeader, nil
|
||||
}
|
||||
// Frame headers for key frames are an additional 7 bytes long.
|
||||
b = d.scratch[:7]
|
||||
if err = d.r.ReadFull(b); err != nil {
|
||||
return
|
||||
}
|
||||
// Check the magic sync code.
|
||||
if b[0] != 0x9d || b[1] != 0x01 || b[2] != 0x2a {
|
||||
err = errors.New("vp8: invalid format")
|
||||
return
|
||||
}
|
||||
d.frameHeader.Width = int(b[4]&0x3f)<<8 | int(b[3])
|
||||
d.frameHeader.Height = int(b[6]&0x3f)<<8 | int(b[5])
|
||||
d.frameHeader.XScale = b[4] >> 6
|
||||
d.frameHeader.YScale = b[6] >> 6
|
||||
d.mbw = (d.frameHeader.Width + 0x0f) >> 4
|
||||
d.mbh = (d.frameHeader.Height + 0x0f) >> 4
|
||||
d.segmentHeader = segmentHeader{
|
||||
prob: [3]uint8{0xff, 0xff, 0xff},
|
||||
}
|
||||
d.tokenProb = defaultTokenProb
|
||||
d.segment = 0
|
||||
return d.frameHeader, nil
|
||||
}
|
||||
|
||||
// ensureImg ensures that d.img is large enough to hold the decoded frame.
|
||||
func (d *Decoder) ensureImg() {
|
||||
if d.img != nil {
|
||||
p0, p1 := d.img.Rect.Min, d.img.Rect.Max
|
||||
if p0.X == 0 && p0.Y == 0 && p1.X >= 16*d.mbw && p1.Y >= 16*d.mbh {
|
||||
return
|
||||
}
|
||||
}
|
||||
m := image.NewYCbCr(image.Rect(0, 0, 16*d.mbw, 16*d.mbh), image.YCbCrSubsampleRatio420)
|
||||
d.img = m.SubImage(image.Rect(0, 0, d.frameHeader.Width, d.frameHeader.Height)).(*image.YCbCr)
|
||||
d.perMBFilterParams = make([]filterParam, d.mbw*d.mbh)
|
||||
d.upMB = make([]mb, d.mbw)
|
||||
}
|
||||
|
||||
// parseSegmentHeader parses the segment header, as specified in section 9.3.
|
||||
func (d *Decoder) parseSegmentHeader() {
|
||||
d.segmentHeader.useSegment = d.fp.readBit(uniformProb)
|
||||
if !d.segmentHeader.useSegment {
|
||||
d.segmentHeader.updateMap = false
|
||||
return
|
||||
}
|
||||
d.segmentHeader.updateMap = d.fp.readBit(uniformProb)
|
||||
if d.fp.readBit(uniformProb) {
|
||||
d.segmentHeader.relativeDelta = !d.fp.readBit(uniformProb)
|
||||
for i := range d.segmentHeader.quantizer {
|
||||
d.segmentHeader.quantizer[i] = int8(d.fp.readOptionalInt(uniformProb, 7))
|
||||
}
|
||||
for i := range d.segmentHeader.filterStrength {
|
||||
d.segmentHeader.filterStrength[i] = int8(d.fp.readOptionalInt(uniformProb, 6))
|
||||
}
|
||||
}
|
||||
if !d.segmentHeader.updateMap {
|
||||
return
|
||||
}
|
||||
for i := range d.segmentHeader.prob {
|
||||
if d.fp.readBit(uniformProb) {
|
||||
d.segmentHeader.prob[i] = uint8(d.fp.readUint(uniformProb, 8))
|
||||
} else {
|
||||
d.segmentHeader.prob[i] = 0xff
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// parseFilterHeader parses the filter header, as specified in section 9.4.
|
||||
func (d *Decoder) parseFilterHeader() {
|
||||
d.filterHeader.simple = d.fp.readBit(uniformProb)
|
||||
d.filterHeader.level = int8(d.fp.readUint(uniformProb, 6))
|
||||
d.filterHeader.sharpness = uint8(d.fp.readUint(uniformProb, 3))
|
||||
d.filterHeader.useLFDelta = d.fp.readBit(uniformProb)
|
||||
if d.filterHeader.useLFDelta && d.fp.readBit(uniformProb) {
|
||||
for i := range d.filterHeader.refLFDelta {
|
||||
d.filterHeader.refLFDelta[i] = int8(d.fp.readOptionalInt(uniformProb, 6))
|
||||
}
|
||||
for i := range d.filterHeader.modeLFDelta {
|
||||
d.filterHeader.modeLFDelta[i] = int8(d.fp.readOptionalInt(uniformProb, 6))
|
||||
}
|
||||
}
|
||||
if d.filterHeader.level == 0 {
|
||||
return
|
||||
}
|
||||
if d.segmentHeader.useSegment {
|
||||
for i := range d.filterHeader.perSegmentLevel {
|
||||
strength := d.segmentHeader.filterStrength[i]
|
||||
if d.segmentHeader.relativeDelta {
|
||||
strength += d.filterHeader.level
|
||||
}
|
||||
d.filterHeader.perSegmentLevel[i] = strength
|
||||
}
|
||||
} else {
|
||||
d.filterHeader.perSegmentLevel[0] = d.filterHeader.level
|
||||
}
|
||||
d.computeFilterParams()
|
||||
}
|
||||
|
||||
// parseOtherPartitions parses the other partitions, as specified in section 9.5.
|
||||
func (d *Decoder) parseOtherPartitions() error {
|
||||
const maxNOP = 1 << 3
|
||||
var partLens [maxNOP]int
|
||||
d.nOP = 1 << d.fp.readUint(uniformProb, 2)
|
||||
|
||||
// The final partition length is implied by the remaining chunk data
|
||||
// (d.r.n) and the other d.nOP-1 partition lengths. Those d.nOP-1 partition
|
||||
// lengths are stored as 24-bit uints, i.e. up to 16 MiB per partition.
|
||||
n := 3 * (d.nOP - 1)
|
||||
partLens[d.nOP-1] = d.r.n - n
|
||||
if partLens[d.nOP-1] < 0 {
|
||||
return io.ErrUnexpectedEOF
|
||||
}
|
||||
if n > 0 {
|
||||
buf := make([]byte, n)
|
||||
if err := d.r.ReadFull(buf); err != nil {
|
||||
return err
|
||||
}
|
||||
for i := 0; i < d.nOP-1; i++ {
|
||||
pl := int(buf[3*i+0]) | int(buf[3*i+1])<<8 | int(buf[3*i+2])<<16
|
||||
if pl > partLens[d.nOP-1] {
|
||||
return io.ErrUnexpectedEOF
|
||||
}
|
||||
partLens[i] = pl
|
||||
partLens[d.nOP-1] -= pl
|
||||
}
|
||||
}
|
||||
|
||||
// We check if the final partition length can also fit into a 24-bit uint.
|
||||
// Strictly speaking, this isn't part of the spec, but it guards against a
|
||||
// malicious WEBP image that is too large to ReadFull the encoded DCT
|
||||
// coefficients into memory, whether that's because the actual WEBP file is
|
||||
// too large, or whether its RIFF metadata lists too large a chunk.
|
||||
if 1<<24 <= partLens[d.nOP-1] {
|
||||
return errors.New("vp8: too much data to decode")
|
||||
}
|
||||
|
||||
buf := make([]byte, d.r.n)
|
||||
if err := d.r.ReadFull(buf); err != nil {
|
||||
return err
|
||||
}
|
||||
for i, pl := range partLens {
|
||||
if i == d.nOP {
|
||||
break
|
||||
}
|
||||
d.op[i].init(buf[:pl])
|
||||
buf = buf[pl:]
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// parseOtherHeaders parses header information other than the frame header.
|
||||
func (d *Decoder) parseOtherHeaders() error {
|
||||
// Initialize and parse the first partition.
|
||||
firstPartition := make([]byte, d.frameHeader.FirstPartitionLen)
|
||||
if err := d.r.ReadFull(firstPartition); err != nil {
|
||||
return err
|
||||
}
|
||||
d.fp.init(firstPartition)
|
||||
if d.frameHeader.KeyFrame {
|
||||
// Read and ignore the color space and pixel clamp values. They are
|
||||
// specified in section 9.2, but are unimplemented.
|
||||
d.fp.readBit(uniformProb)
|
||||
d.fp.readBit(uniformProb)
|
||||
}
|
||||
d.parseSegmentHeader()
|
||||
d.parseFilterHeader()
|
||||
if err := d.parseOtherPartitions(); err != nil {
|
||||
return err
|
||||
}
|
||||
d.parseQuant()
|
||||
if !d.frameHeader.KeyFrame {
|
||||
// Golden and AltRef frames are specified in section 9.7.
|
||||
// TODO(nigeltao): implement. Note that they are only used for video, not still images.
|
||||
return errors.New("vp8: Golden / AltRef frames are not implemented")
|
||||
}
|
||||
// Read and ignore the refreshLastFrameBuffer bit, specified in section 9.8.
|
||||
// It applies only to video, and not still images.
|
||||
d.fp.readBit(uniformProb)
|
||||
d.parseTokenProb()
|
||||
d.useSkipProb = d.fp.readBit(uniformProb)
|
||||
if d.useSkipProb {
|
||||
d.skipProb = uint8(d.fp.readUint(uniformProb, 8))
|
||||
}
|
||||
if d.fp.unexpectedEOF {
|
||||
return io.ErrUnexpectedEOF
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// DecodeFrame decodes the frame and returns it as an YCbCr image.
|
||||
// The image's contents are valid up until the next call to Decoder.Init.
|
||||
func (d *Decoder) DecodeFrame() (*image.YCbCr, error) {
|
||||
d.ensureImg()
|
||||
if err := d.parseOtherHeaders(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
// Reconstruct the rows.
|
||||
for mbx := 0; mbx < d.mbw; mbx++ {
|
||||
d.upMB[mbx] = mb{}
|
||||
}
|
||||
for mby := 0; mby < d.mbh; mby++ {
|
||||
d.leftMB = mb{}
|
||||
for mbx := 0; mbx < d.mbw; mbx++ {
|
||||
skip := d.reconstruct(mbx, mby)
|
||||
fs := d.filterParams[d.segment][btou(!d.usePredY16)]
|
||||
fs.inner = fs.inner || !skip
|
||||
d.perMBFilterParams[d.mbw*mby+mbx] = fs
|
||||
}
|
||||
}
|
||||
if d.fp.unexpectedEOF {
|
||||
return nil, io.ErrUnexpectedEOF
|
||||
}
|
||||
for i := 0; i < d.nOP; i++ {
|
||||
if d.op[i].unexpectedEOF {
|
||||
return nil, io.ErrUnexpectedEOF
|
||||
}
|
||||
}
|
||||
// Apply the loop filter.
|
||||
//
|
||||
// Even if we are using per-segment levels, section 15 says that "loop
|
||||
// filtering must be skipped entirely if loop_filter_level at either the
|
||||
// frame header level or macroblock override level is 0".
|
||||
if d.filterHeader.level != 0 {
|
||||
if d.filterHeader.simple {
|
||||
d.simpleFilter()
|
||||
} else {
|
||||
d.normalFilter()
|
||||
}
|
||||
}
|
||||
return d.img, nil
|
||||
}
|
Reference in New Issue
Block a user