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fq/format/av1/av1_obu.go
2023-05-01 13:19:04 +02:00

79 lines
1.8 KiB
Go

package av1
import (
"github.com/wader/fq/format"
"github.com/wader/fq/pkg/decode"
"github.com/wader/fq/pkg/interp"
"github.com/wader/fq/pkg/scalar"
)
func init() {
interp.RegisterFormat(
format.AV1_OBU,
&decode.Format{
Description: "AV1 Open Bitstream Unit",
DecodeFn: obuDecode,
})
}
const (
OBU_SEQUENCE_HEADER = 1
OBU_TEMPORAL_DELIMITER = 2
OBU_FRAME_HEADER = 3
OBU_TILE_GROUP = 4
OBU_METADATA = 5
OBU_FRAME = 6
OBU_REDUNDANT_FRAME_HEADER = 7
OBU_TILE_LIST = 8
OBU_PADDING = 15
)
var obuTypeNames = scalar.UintMapSymStr{
OBU_SEQUENCE_HEADER: "OBU_SEQUENCE_HEADER",
OBU_TEMPORAL_DELIMITER: "OBU_TEMPORAL_DELIMITER",
OBU_FRAME_HEADER: "OBU_FRAME_HEADER",
OBU_TILE_GROUP: "OBU_TILE_GROUP",
OBU_METADATA: "OBU_METADATA",
OBU_FRAME: "OBU_FRAME",
OBU_REDUNDANT_FRAME_HEADER: "OBU_REDUNDANT_FRAME_HEADER",
OBU_TILE_LIST: "OBU_TILE_LIST",
OBU_PADDING: "OBU_PADDING",
}
func obuDecode(d *decode.D) any {
var obuType uint64
var obuSize int64
hasExtension := false
hasSizeField := false
d.FieldStruct("header", func(d *decode.D) {
d.FieldU1("forbidden_bit")
obuType = d.FieldU4("type", obuTypeNames)
hasExtension = d.FieldBool("extension_flag")
hasSizeField = d.FieldBool("has_size_field")
d.FieldU1("reserved_1bit")
if hasExtension {
d.FieldU3("temporal_id")
d.FieldU2("spatial_id")
d.FieldU3("extension_header_reserved_3bits")
}
})
if hasSizeField {
obuSize = int64(d.FieldULEB128("size"))
} else {
obuSize = d.BitsLeft() / 8
if hasExtension {
obuSize--
}
}
_ = obuType
if d.BitsLeft() > 0 {
d.FieldRawLen("data", obuSize*8)
}
return nil
}