mirror of
https://github.com/cwinfo/matterbridge.git
synced 2024-11-10 11:00:27 +00:00
26a7e35f27
* 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
99 lines
3.0 KiB
Go
99 lines
3.0 KiB
Go
// 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
|
|
|
|
// This file implements parsing the quantization factors.
|
|
|
|
// quant are DC/AC quantization factors.
|
|
type quant struct {
|
|
y1 [2]uint16
|
|
y2 [2]uint16
|
|
uv [2]uint16
|
|
}
|
|
|
|
// clip clips x to the range [min, max] inclusive.
|
|
func clip(x, min, max int32) int32 {
|
|
if x < min {
|
|
return min
|
|
}
|
|
if x > max {
|
|
return max
|
|
}
|
|
return x
|
|
}
|
|
|
|
// parseQuant parses the quantization factors, as specified in section 9.6.
|
|
func (d *Decoder) parseQuant() {
|
|
baseQ0 := d.fp.readUint(uniformProb, 7)
|
|
dqy1DC := d.fp.readOptionalInt(uniformProb, 4)
|
|
const dqy1AC = 0
|
|
dqy2DC := d.fp.readOptionalInt(uniformProb, 4)
|
|
dqy2AC := d.fp.readOptionalInt(uniformProb, 4)
|
|
dquvDC := d.fp.readOptionalInt(uniformProb, 4)
|
|
dquvAC := d.fp.readOptionalInt(uniformProb, 4)
|
|
for i := 0; i < nSegment; i++ {
|
|
q := int32(baseQ0)
|
|
if d.segmentHeader.useSegment {
|
|
if d.segmentHeader.relativeDelta {
|
|
q += int32(d.segmentHeader.quantizer[i])
|
|
} else {
|
|
q = int32(d.segmentHeader.quantizer[i])
|
|
}
|
|
}
|
|
d.quant[i].y1[0] = dequantTableDC[clip(q+dqy1DC, 0, 127)]
|
|
d.quant[i].y1[1] = dequantTableAC[clip(q+dqy1AC, 0, 127)]
|
|
d.quant[i].y2[0] = dequantTableDC[clip(q+dqy2DC, 0, 127)] * 2
|
|
d.quant[i].y2[1] = dequantTableAC[clip(q+dqy2AC, 0, 127)] * 155 / 100
|
|
if d.quant[i].y2[1] < 8 {
|
|
d.quant[i].y2[1] = 8
|
|
}
|
|
// The 117 is not a typo. The dequant_init function in the spec's Reference
|
|
// Decoder Source Code (http://tools.ietf.org/html/rfc6386#section-9.6 Page 145)
|
|
// says to clamp the LHS value at 132, which is equal to dequantTableDC[117].
|
|
d.quant[i].uv[0] = dequantTableDC[clip(q+dquvDC, 0, 117)]
|
|
d.quant[i].uv[1] = dequantTableAC[clip(q+dquvAC, 0, 127)]
|
|
}
|
|
}
|
|
|
|
// The dequantization tables are specified in section 14.1.
|
|
var (
|
|
dequantTableDC = [128]uint16{
|
|
4, 5, 6, 7, 8, 9, 10, 10,
|
|
11, 12, 13, 14, 15, 16, 17, 17,
|
|
18, 19, 20, 20, 21, 21, 22, 22,
|
|
23, 23, 24, 25, 25, 26, 27, 28,
|
|
29, 30, 31, 32, 33, 34, 35, 36,
|
|
37, 37, 38, 39, 40, 41, 42, 43,
|
|
44, 45, 46, 46, 47, 48, 49, 50,
|
|
51, 52, 53, 54, 55, 56, 57, 58,
|
|
59, 60, 61, 62, 63, 64, 65, 66,
|
|
67, 68, 69, 70, 71, 72, 73, 74,
|
|
75, 76, 76, 77, 78, 79, 80, 81,
|
|
82, 83, 84, 85, 86, 87, 88, 89,
|
|
91, 93, 95, 96, 98, 100, 101, 102,
|
|
104, 106, 108, 110, 112, 114, 116, 118,
|
|
122, 124, 126, 128, 130, 132, 134, 136,
|
|
138, 140, 143, 145, 148, 151, 154, 157,
|
|
}
|
|
dequantTableAC = [128]uint16{
|
|
4, 5, 6, 7, 8, 9, 10, 11,
|
|
12, 13, 14, 15, 16, 17, 18, 19,
|
|
20, 21, 22, 23, 24, 25, 26, 27,
|
|
28, 29, 30, 31, 32, 33, 34, 35,
|
|
36, 37, 38, 39, 40, 41, 42, 43,
|
|
44, 45, 46, 47, 48, 49, 50, 51,
|
|
52, 53, 54, 55, 56, 57, 58, 60,
|
|
62, 64, 66, 68, 70, 72, 74, 76,
|
|
78, 80, 82, 84, 86, 88, 90, 92,
|
|
94, 96, 98, 100, 102, 104, 106, 108,
|
|
110, 112, 114, 116, 119, 122, 125, 128,
|
|
131, 134, 137, 140, 143, 146, 149, 152,
|
|
155, 158, 161, 164, 167, 170, 173, 177,
|
|
181, 185, 189, 193, 197, 201, 205, 209,
|
|
213, 217, 221, 225, 229, 234, 239, 245,
|
|
249, 254, 259, 264, 269, 274, 279, 284,
|
|
}
|
|
)
|