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mirror of https://github.com/wader/fq.git synced 2024-12-25 14:23:18 +03:00
fq/format/vpx/vp8_frame.go
2021-09-12 13:08:51 +02:00

71 lines
1.7 KiB
Go

package vpx
// https://tools.ietf.org/html/rfc6386
import (
"github.com/wader/fq/format"
"github.com/wader/fq/format/registry"
"github.com/wader/fq/pkg/decode"
)
// TODO: vpx frame?
func init() {
registry.MustRegister(&decode.Format{
Name: format.VP8_FRAME,
Description: "VP8 frame",
DecodeFn: vp8Decode,
})
}
func vp8Decode(d *decode.D, in interface{}) interface{} {
var isKeyFrame bool
versions := map[uint64]struct {
reconstruction string
loop string
}{
0: {"Bicubic", "Normal"},
1: {"Bilinear", "Simple"},
2: {"Bilinear", "None"},
3: {"None", "None"},
}
d.FieldStructFn("tag", func(d *decode.D) {
// first_part_size is not contiguous bits
firstPartSize0 := d.FieldU3("first_part_size0")
d.FieldU1("show_frame")
version := d.FieldU3("version")
keyFrameV, _ := d.FieldBoolMapFn("frame_type", "non_key_frame", "key_frame", d.Bool)
firstPartSize1 := d.FieldU16LE("first_part_size1")
firstPartSize := firstPartSize0 | firstPartSize1<<3
d.FieldValueU("first_part_size", firstPartSize, "")
isKeyFrame = !keyFrameV
if v, ok := versions[version]; ok {
d.FieldValueStr("reconstruction", v.reconstruction, "")
d.FieldValueStr("loop", v.loop, "")
}
})
if isKeyFrame {
d.FieldValidateUFn("start_code", 0x9d012a, d.U24)
// width and height are not contiguous bits
width0 := d.FieldU8("width0")
d.FieldU2("horizontal_scale")
width1 := d.FieldU6("width1")
d.FieldValueU("width", width0|width1<<8, "")
height0 := d.FieldU8("height0")
d.FieldU2("vertical_scale")
height1 := d.FieldU6("height1")
d.FieldValueU("height", height0|height1<<8, "")
}
d.FieldBitBufLen("data", d.BitsLeft())
return nil
}