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mirror of https://github.com/wader/fq.git synced 2024-12-26 15:02:28 +03:00
fq/format/mp4/boxes.go
2022-07-07 19:02:10 +02:00

1498 lines
43 KiB
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package mp4
// TODO: flags?
import (
"bytes"
"fmt"
"time"
"github.com/wader/fq/format"
"github.com/wader/fq/pkg/decode"
"github.com/wader/fq/pkg/scalar"
)
// TODO: keep track of list of sampleSize/entries instead and change sample read code
const maxSampleEntryCount = 10_000_000
var boxAliases = map[string]string{
"styp": "ftyp",
}
const (
boxSizeRestOfFile = 0
boxSizeUse64bitSize = 1
)
var boxSizeNames = scalar.UToDescription{
boxSizeRestOfFile: "Rest of file",
boxSizeUse64bitSize: "Use 64 bit size",
}
var mediaTimeNames = scalar.SToDescription{
-1: "empty",
}
var subTypeNames = scalar.StrToDescription{
"alis": "Alias Data",
"camm": "Camera Metadata",
"crsm": "Clock Reference",
"data": "Data",
"hint": "Hint Track",
"ipsm": "IPMP",
"m7sm": "MPEG-7 Stream",
"mdir": "Metadata",
"mdta": "Metadata Tags",
"meta": "NRT Metadata",
"mjsm": "MPEG-J",
"nrtm": "Non-Real Time Metadata",
"ocsm": "Object Content",
"odsm": "Object Descriptor",
"pict": "Picture",
"priv": "Private",
"psmd": "Panasonic Static Metadata",
"sbtl": "Subtitle",
"sdsm": "Scene Description",
"soun": "Audio Track",
"subp": "Subpicture",
"text": "Text",
"tmcd": "Time Code",
"url ": "URL",
"vide": "Video Track",
}
var (
uuidIsmlManifestBytes = [16]byte{0xa5, 0xd4, 0x0b, 0x30, 0xe8, 0x14, 0x11, 0xdd, 0xba, 0x2f, 0x08, 0x00, 0x20, 0x0c, 0x9a, 0x66}
uuidXmpBytes = [16]byte{0xbe, 0x7a, 0xcf, 0xcb, 0x97, 0xa9, 0x42, 0xe8, 0x9c, 0x71, 0x99, 0x94, 0x91, 0xe3, 0xaf, 0xac}
uuidSphericalBytes = [16]byte{0xff, 0xcc, 0x82, 0x63, 0xf8, 0x55, 0x4a, 0x93, 0x88, 0x14, 0x58, 0x7a, 0x02, 0x52, 0x1f, 0xdd}
uuidPspUsmtBytes = [16]byte{0x55, 0x53, 0x4d, 0x54, 0x21, 0xd2, 0x4f, 0xce, 0xbb, 0x88, 0x69, 0x5c, 0xfa, 0xc9, 0xc7, 0x40}
uuidTfxdBytes = [16]byte{0x6d, 0x1d, 0x9b, 0x05, 0x42, 0xd5, 0x44, 0xe6, 0x80, 0xe2, 0x14, 0x1d, 0xaf, 0xf7, 0x57, 0xb2}
uuidTfrfBytes = [16]byte{0xd4, 0x80, 0x7e, 0xf2, 0xca, 0x39, 0x46, 0x95, 0x8e, 0x54, 0x26, 0xcb, 0x9e, 0x46, 0xa7, 0x9f}
uuidProfBytes = [16]byte{0x50, 0x52, 0x4f, 0x46, 0x21, 0xd2, 0x4f, 0xce, 0xbb, 0x88, 0x69, 0x5c, 0xfa, 0xc9, 0xc7, 0x40}
uuidIpodBytes = [16]byte{0x6b, 0x68, 0x40, 0xf2, 0x5f, 0x24, 0x4f, 0xc5, 0xba, 0x39, 0xa5, 0x1b, 0xcf, 0x03, 0x23, 0xf3}
)
var uuidNames = scalar.BytesToScalar{
{Bytes: uuidIsmlManifestBytes[:], Scalar: scalar.S{Sym: "isml_manifest"}},
{Bytes: uuidXmpBytes[:], Scalar: scalar.S{Sym: "xmp"}},
{Bytes: uuidSphericalBytes[:], Scalar: scalar.S{Sym: "spherical"}},
{Bytes: uuidPspUsmtBytes[:], Scalar: scalar.S{Sym: "psp_usmt"}},
{Bytes: uuidTfxdBytes[:], Scalar: scalar.S{Sym: "tfxd"}},
{Bytes: uuidTfrfBytes[:], Scalar: scalar.S{Sym: "tfrf"}},
{Bytes: uuidProfBytes[:], Scalar: scalar.S{Sym: "prof"}},
{Bytes: uuidIpodBytes[:], Scalar: scalar.S{Sym: "ipod"}},
}
// ISO 639-2/T language code 3 * 5bit packed uint + 1 zero bit
func decodeLang(d *decode.D) string {
d.U1()
return string([]byte{
byte(d.U5()) + 0x60,
byte(d.U5()) + 0x60,
byte(d.U5()) + 0x60},
)
}
// Quicktime time seconds in January 1, 1904 UTC
var quicktimeEpochDate = time.Date(1904, time.January, 4, 0, 0, 0, 0, time.UTC)
var quicktimeEpoch = scalar.DescriptionActualUTime(quicktimeEpochDate, time.RFC3339)
func decodeFieldMatrix(d *decode.D, name string) {
d.FieldStruct(name, func(d *decode.D) {
d.FieldFP32("a")
d.FieldFP32("b")
d.FieldFP("u", 32, 30)
d.FieldFP32("c")
d.FieldFP32("d")
d.FieldFP("v", 32, 30)
d.FieldFP32("x")
d.FieldFP32("y")
d.FieldFP("w", 32, 30)
})
}
func decodeBoxWithParentData(ctx *decodeContext, d *decode.D, parentData any) {
var typ string
var dataSize uint64
boxSize := d.FieldU32("size", boxSizeNames)
typ = d.FieldUTF8("type", 4, boxDescriptions)
switch boxSize {
case boxSizeRestOfFile:
dataSize = uint64(d.Len()-d.Pos()) / 8
case boxSizeUse64bitSize:
boxSize = d.FieldU64("size64")
dataSize = boxSize - 16
default:
dataSize = boxSize - 8
}
if ctx.opts.AllowTruncated && dataSize > uint64(d.BitsLeft()/8) {
dataSize = uint64(d.BitsLeft() / 8)
}
// TODO: not sure about this
switch {
case typ == "<22>too":
typ = "_apple_list"
case typ[0] == 0xa9:
typ = "_apple_entry"
}
if a, ok := boxAliases[typ]; ok {
typ = a
}
if parentData != nil {
ctx.path[len(ctx.path)-1].data = parentData
}
ctx.path = append(ctx.path, pathEntry{typ: typ, data: parentData})
if decodeFn, ok := boxDecoders[typ]; ok {
d.FramedFn(int64(dataSize*8), func(d *decode.D) {
decodeFn(ctx, d)
})
} else {
d.FieldRawLen("data", int64(dataSize*8))
}
ctx.path = ctx.path[0 : len(ctx.path)-1]
}
func decodeBoxes(ctx *decodeContext, d *decode.D) {
decodeBoxesWithParentData(ctx, d, nil)
}
func decodeBoxesWithParentData(ctx *decodeContext, d *decode.D, parentData any) {
d.FieldStructArrayLoop("boxes", "box", func() bool { return d.BitsLeft() >= 8*8 }, func(d *decode.D) {
decodeBoxWithParentData(ctx, d, parentData)
})
if d.BitsLeft() > 0 {
// "Some sample descriptions terminate with four zero bytes that are not otherwise indicated."
if d.BitsLeft() >= 32 && d.PeekBits(32) == 0 {
d.FieldU32("zero_terminator")
}
if d.BitsLeft() > 0 {
d.FieldRawLen("padding", d.BitsLeft())
}
}
}
var boxDecoders map[string]func(ctx *decodeContext, d *decode.D)
type irefBox struct {
version int
}
type trakBox struct {
trackID int
}
type moofBox struct {
offset int64
}
type trafBox struct {
trackID int
baseDataOffset int64
moof *moof
}
func irefEntryDecode(ctx *decodeContext, d *decode.D) {
irefBox, ok := ctx.parent().data.(*irefBox)
if !ok {
d.FieldRawLen("data", d.BitsLeft())
return
}
idSize := 16
if irefBox.version != 0 {
idSize = 32
}
d.FieldU("from_id", idSize)
count := d.FieldU16("count")
d.FieldArray("ids", func(d *decode.D) {
for i := uint64(0); i < count; i++ {
d.FieldU("id", idSize)
}
})
}
func init() {
boxDecoders = map[string]func(ctx *decodeContext, d *decode.D){
"ftyp": func(_ *decodeContext, d *decode.D) {
d.FieldUTF8("major_brand", 4)
d.FieldU32("minor_version")
numBrands := d.BitsLeft() / 8 / 4
var i int64
d.FieldArrayLoop("brands", func() bool { return i < numBrands }, func(d *decode.D) {
d.FieldUTF8("brand", 4, brandDescriptions, scalar.ActualTrimSpace)
i++
})
},
"mvhd": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
switch version {
case 0:
d.FieldU32("creation_time", quicktimeEpoch)
d.FieldU32("modification_time", quicktimeEpoch)
d.FieldU32("time_scale")
d.FieldU32("duration")
case 1:
d.FieldU64("creation_time", quicktimeEpoch)
d.FieldU64("modification_time", quicktimeEpoch)
d.FieldU32("time_scale")
d.FieldU64("duration")
default:
return
}
d.FieldFP32("preferred_rate")
d.FieldFP16("preferred_volume")
d.FieldUTF8("reserved", 10)
decodeFieldMatrix(d, "matrix_structure")
d.FieldU32("preview_time")
d.FieldU32("preview_duration")
d.FieldU32("poster_time")
d.FieldU32("selection_time")
d.FieldU32("selection_duration")
d.FieldU32("current_time")
d.FieldU32("next_track_id")
},
"trak": func(ctx *decodeContext, d *decode.D) {
decodeBoxesWithParentData(ctx, d, &trakBox{})
},
"edts": decodeBoxes,
"elst": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
entryCount := d.FieldU32("entry_count")
var i uint64
d.FieldStructArrayLoop("entries", "entry", func() bool { return i < entryCount }, func(d *decode.D) {
d.FieldS32("segment_duration")
d.FieldSFn("media_time", func(d *decode.D) int64 {
var t int64
if version == 0 {
t = d.S32()
} else {
t = d.S64()
}
return t
}, mediaTimeNames)
d.FieldFP32("media_rate")
i++
})
},
"tref": decodeBoxes,
"tkhd": func(ctx *decodeContext, d *decode.D) {
var trackID int
version := d.FieldU8("version")
d.FieldU24("flags")
switch version {
case 0:
d.FieldU32("creation_time", quicktimeEpoch)
d.FieldU32("modification_time", quicktimeEpoch)
trackID = int(d.FieldU32("track_id"))
d.FieldU32("reserved1")
d.FieldU32("duration")
case 1:
d.FieldU64("creation_time", quicktimeEpoch)
d.FieldU64("modification_time", quicktimeEpoch)
trackID = int(d.FieldU32("track_id"))
d.FieldU32("reserved1")
d.FieldU64("duration")
default:
return
}
d.FieldRawLen("reserved2", 8*8)
d.FieldU16("layer")
d.FieldU16("alternate_group")
d.FieldFP16("volume")
d.FieldU16("reserved3")
decodeFieldMatrix(d, "matrix_structure")
d.FieldFP32("track_width")
d.FieldFP32("track_height")
if t := ctx.currentTrakBox(); t != nil {
t.trackID = trackID
_ = ctx.currentTrack()
}
},
"mdia": decodeBoxes,
"mdhd": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
// TODO: timestamps
switch version {
case 0:
d.FieldU32("creation_time", quicktimeEpoch)
d.FieldU32("modification_time", quicktimeEpoch)
d.FieldU32("time_scale")
d.FieldU32("duration")
case 1:
d.FieldU64("creation_time", quicktimeEpoch)
d.FieldU64("modification_time", quicktimeEpoch)
d.FieldU32("time_scale")
d.FieldU64("duration")
default:
return
}
d.FieldStrFn("language", decodeLang)
d.FieldU16("quality")
},
"vmhd": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldU16("graphicsmode")
d.FieldArray("opcolor", func(d *decode.D) {
// TODO: is FP16?
d.FieldU16("value")
d.FieldU16("value")
d.FieldU16("value")
})
},
"hdlr": func(ctx *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldUTF8NullFixedLen("component_type", 4)
subType := d.FieldUTF8("component_subtype", 4, subTypeNames, scalar.ActualTrimSpace)
d.FieldUTF8NullFixedLen("component_manufacturer", 4)
d.FieldU32("component_flags")
d.FieldU32("component_flags_mask")
// TODO: sometimes has a length prefix byte, how to know?
d.FieldUTF8NullFixedLen("component_name", int(d.BitsLeft()/8))
if t := ctx.currentTrack(); t != nil {
// component_type seems to be all zero sometimes so can't look for "mhlr"
switch subType {
case "vide", "soun":
t.subType = subType
}
}
},
"minf": decodeBoxes,
"dinf": decodeBoxes,
"dref": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
entryCount := d.FieldU32("entry_count")
var i uint64
d.FieldStructArrayLoop("boxes", "box", func() bool { return i < entryCount }, func(d *decode.D) {
size := d.FieldU32("size")
d.FieldUTF8("type", 4)
d.FieldU8("version")
d.FieldU24("flags")
dataSize := size - 12
d.FieldRawLen("data", int64(dataSize*8))
i++
})
},
"stbl": decodeBoxes,
"stsd": func(ctx *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
entryCount := d.FieldU32("entry_count")
var i uint64
// note called "boxes" here instead of "sample_descriptions" and data format is named "type".
// this is to make it easier to threat them as normal boxes
d.FieldArrayLoop("boxes", func() bool { return i < entryCount }, func(d *decode.D) {
d.FieldStruct("box", func(d *decode.D) {
size := d.FieldU32("size")
dataFormat := d.FieldUTF8("type", 4)
subType := ""
if t := ctx.currentTrack(); t != nil {
t.sampleDescriptions = append(t.sampleDescriptions, sampleDescription{
dataFormat: dataFormat,
})
subType = t.subType
}
d.FramedFn(int64(size-8)*8, func(d *decode.D) {
d.FieldRawLen("reserved", 6*8)
d.FieldU16("data_reference_index")
switch subType {
case "soun", "vide":
version := d.FieldU16("version")
d.FieldU16("revision_level")
d.FieldU32("max_packet_size") // TODO: vendor for some subtype?
switch subType {
case "soun":
// AudioSampleEntry
// https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap3/qtff3.html#//apple_ref/doc/uid/TP40000939-CH205-SW1
switch version {
case 0:
d.FieldU16("num_audio_channels")
d.FieldU16("sample_size")
d.FieldU16("compression_id")
d.FieldU16("packet_size")
d.FieldFP32("sample_rate")
if d.BitsLeft() > 0 {
decodeBoxes(ctx, d)
}
case 1:
d.FieldU16("num_audio_channels")
d.FieldU16("sample_size")
d.FieldU16("compression_id")
d.FieldU16("packet_size")
d.FieldFP32("sample_rate")
d.FieldU32("samples_per_packet")
d.FieldU32("bytes_per_packet")
d.FieldU32("bytes_per_frame")
d.FieldU32("bytes_per_sample")
if d.BitsLeft() > 0 {
decodeBoxes(ctx, d)
}
case 2:
d.FieldU16("always_3")
d.FieldU16("always_16")
d.FieldU16("always_minus_2") // TODO: as in const -2?
d.FieldU16("always_0")
d.FieldU32("always_65536")
d.FieldU32("size_of_struct_only")
d.FieldF64("audio_sample_rate")
d.FieldU32("num_audio_channels")
d.FieldU32("always_7f000000")
d.FieldU32("const_bits_per_channel")
d.FieldU32("format_specific_flags")
d.FieldU32("const_bytes_per_audio_packet")
d.FieldU32("const_lpcm_frames_per_audio_packet")
if d.BitsLeft() > 0 {
decodeBoxes(ctx, d)
}
default:
d.FieldRawLen("data", d.BitsLeft())
}
case "vide":
// VideoSampleEntry
// TODO: version 0 and 1 same?
switch version {
case 0, 1:
d.FieldU32("temporal_quality")
d.FieldU32("spatial_quality")
d.FieldU16("width")
d.FieldU16("height")
d.FieldFP32("horizontal_resolution")
d.FieldFP32("vertical_resolution")
d.FieldU32("data_size")
d.FieldU16("frame_count")
d.FieldUTF8ShortStringFixedLen("compressor_name", 32)
d.FieldU16("depth")
d.FieldS16("color_table_id")
// TODO: if 0 decode ctab
if d.BitsLeft() > 0 {
decodeBoxes(ctx, d)
}
default:
d.FieldRawLen("data", d.BitsLeft())
}
// case "hint": TODO: Hint entry
default:
d.FieldRawLen("data", d.BitsLeft())
}
default:
d.FieldRawLen("data", d.BitsLeft())
}
})
})
i++
})
},
"avcC": func(ctx *decodeContext, d *decode.D) {
dv, v := d.FieldFormat("descriptor", mpegAVCDCRFormat, nil)
avcDcrOut, ok := v.(format.AvcDcrOut)
if dv != nil && !ok {
panic(fmt.Sprintf("expected AvcDcrOut got %#+v", v))
}
if t := ctx.currentTrack(); t != nil {
t.formatInArg = format.AvcAuIn{LengthSize: avcDcrOut.LengthSize} //nolint:gosimple
}
},
"hvcC": func(ctx *decodeContext, d *decode.D) {
dv, v := d.FieldFormat("descriptor", mpegHEVCDCRFrameFormat, nil)
hevcDcrOut, ok := v.(format.HevcDcrOut)
if dv != nil && !ok {
panic(fmt.Sprintf("expected HevcDcrOut got %#+v", v))
}
if t := ctx.currentTrack(); t != nil {
t.formatInArg = format.HevcAuIn{LengthSize: hevcDcrOut.LengthSize} //nolint:gosimple
}
},
"dfLa": func(ctx *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
dv, v := d.FieldFormat("descriptor", flacMetadatablocksFormat, nil)
flacMetadatablockOut, ok := v.(format.FlacMetadatablocksOut)
if dv != nil && !ok {
panic(fmt.Sprintf("expected FlacMetadatablockOut got %#+v", v))
}
if flacMetadatablockOut.HasStreamInfo {
if t := ctx.currentTrack(); t != nil {
t.formatInArg = format.FlacFrameIn{BitsPerSample: int(flacMetadatablockOut.StreamInfo.BitsPerSample)}
}
}
},
"dOps": func(_ *decodeContext, d *decode.D) {
d.FieldFormat("descriptor", opusPacketFrameFormat, nil)
},
"av1C": func(_ *decodeContext, d *decode.D) {
d.FieldFormat("descriptor", av1CCRFormat, nil)
},
"vpcC": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldFormat("descriptor", vpxCCRFormat, nil)
},
"esds": func(ctx *decodeContext, d *decode.D) {
d.FieldU32("version")
dv, v := d.FieldFormat("descriptor", mpegESFormat, nil)
mpegEsOut, ok := v.(format.MpegEsOut)
if dv != nil && !ok {
panic(fmt.Sprintf("expected mpegEsOut got %#+v", v))
}
if t := ctx.currentTrack(); t != nil && len(mpegEsOut.DecoderConfigs) > 0 {
dc := mpegEsOut.DecoderConfigs[0]
t.objectType = dc.ObjectType
t.formatInArg = format.AACFrameIn{ObjectType: dc.ASCObjectType}
}
},
"stts": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
numEntries := d.FieldU32("entry_count")
var i uint64
d.FieldStructArrayLoop("entries", "entry", func() bool { return i < numEntries }, func(d *decode.D) {
d.FieldU32("count")
d.FieldU32("delta")
i++
})
},
"stsc": func(ctx *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
entryCount := d.FieldU32("entry_count")
var i uint64
d.FieldStructArrayLoop("entries", "entry", func() bool { return i < entryCount }, func(d *decode.D) {
firstChunk := uint32(d.FieldU32("first_chunk"))
samplesPerChunk := uint32(d.FieldU32("samples_per_chunk"))
d.FieldU32("sample_description_id")
if t := ctx.currentTrack(); t != nil {
t.stsc = append(t.stsc, stsc{
firstChunk: int(firstChunk),
samplesPerChunk: int(samplesPerChunk),
})
}
i++
})
},
"stsz": func(ctx *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
// TODO: bytes_per_sample from audio stsd?
sampleSize := d.FieldU32("sample_size")
entryCount := d.FieldU32("entry_count")
t := ctx.currentTrack()
if t != nil && len(t.stsz) > 0 {
d.Errorf("multiple stsz or stz2 boxes")
}
if sampleSize == 0 {
var i uint64
d.FieldArrayLoop("entries", func() bool { return i < entryCount }, func(d *decode.D) {
size := uint32(d.FieldU32("size"))
if t != nil {
t.stsz = append(t.stsz, stsz{
size: int64(size),
count: 1,
})
}
i++
})
} else {
if t != nil {
t.stsz = append(t.stsz, stsz{
size: int64(sampleSize),
count: int(entryCount),
})
}
}
},
"stz2": func(ctx *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
fieldSize := d.FieldU32("field_size")
if fieldSize > 16 {
d.Errorf("field_size %d > 16", fieldSize)
}
entryCount := d.FieldU32("entry_count")
var i uint64
t := ctx.currentTrack()
if t != nil && len(t.stsz) > 0 {
d.Errorf("multiple stsz or stz2 boxes")
}
d.FieldArrayLoop("entries", func() bool { return i < entryCount }, func(d *decode.D) {
size := uint32(d.FieldU("size", int(fieldSize)))
if t != nil {
t.stsz = append(t.stsz, stsz{
size: int64(size),
count: 1,
})
}
i++
})
},
"stco": func(ctx *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
entryCount := d.FieldU32("entry_count")
var i uint64
t := ctx.currentTrack()
d.FieldArrayLoop("entries", func() bool { return i < entryCount }, func(d *decode.D) {
chunkOffset := d.FieldU32("chunk_offset")
if t != nil {
t.stco = append(t.stco, int64(chunkOffset))
}
i++
})
},
"stss": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
entryCount := d.FieldU32("entry_count")
d.FieldArray("entries", func(d *decode.D) {
for i := uint64(0); i < entryCount; i++ {
d.FieldU32("sample_number")
}
})
},
"sdtp": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
// TODO: should be count from stsz
// TODO: can we know count here or do we need to defer decoding somehow?
d.FieldArray("entries", func(d *decode.D) {
for d.NotEnd() {
d.FieldStruct("entry", func(d *decode.D) {
d.FieldU2("reserved")
values := scalar.UToSymStr{
0: "unknown",
1: "yes",
2: "no",
}
d.FieldU2("sample_depends_on", values)
d.FieldU2("sample_is_depended_on", values)
d.FieldU2("sample_has_redundancy", values)
})
}
})
},
"ctts": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
entryCount := d.FieldU32("entry_count")
var i uint64
d.FieldStructArrayLoop("entries", "entry", func() bool { return i < entryCount }, func(d *decode.D) {
d.FieldS32("sample_count")
d.FieldS32("sample_offset")
i++
})
},
// TODO: refactor: merge with stco?
"co64": func(ctx *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
entryCount := d.FieldU32("entry_count")
var i uint64
t := ctx.currentTrack()
d.FieldArrayLoop("entries", func() bool { return i < entryCount }, func(d *decode.D) {
offset := d.FieldU64("offset")
if t != nil {
t.stco = append(t.stco, int64(offset))
}
i++
})
},
"sidx": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
d.FieldU32("reference_id")
d.FieldU32("timescale")
if version == 0 {
d.FieldU32("pts")
d.FieldU32("offset")
} else {
d.FieldU64("pts")
d.FieldU64("offset")
}
d.FieldU16("reserved")
numEntries := d.FieldU16("entry_count")
var i uint64
d.FieldStructArrayLoop("entries", "entry", func() bool { return i < numEntries }, func(d *decode.D) {
d.FieldU1("reference_type")
d.FieldU31("size")
d.FieldU32("duration")
d.FieldU1("starts_with_sap")
d.FieldU3("sap_type")
d.FieldU28("sap_delta_time")
i++
})
},
"udta": decodeBoxes,
"meta": func(ctx *decodeContext, d *decode.D) {
// TODO: meta box sometimes has a 4 byte unknown field? (flag/version?)
maybeFlags := d.PeekBits(32)
if maybeFlags == 0 {
// TODO: rename?
d.FieldU32("maybe_flags")
}
decodeBoxes(ctx, d)
},
"ilst": decodeBoxes,
"_apple_list": decodeBoxes,
"_apple_entry": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldUTF8("data", int(d.BitsLeft()/8))
},
"data": func(ctx *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldU32("reserved")
if ctx.isParent("covr") {
d.FieldFormatOrRawLen("data", d.BitsLeft(), imageFormat, nil)
} else {
d.FieldUTF8("data", int(d.BitsLeft()/8))
}
},
"moov": decodeBoxes,
"moof": func(ctx *decodeContext, d *decode.D) {
offset := (d.Pos() / 8) - 8
decodeBoxesWithParentData(ctx, d, &moofBox{offset: offset})
},
// Track Fragment
"traf": func(ctx *decodeContext, d *decode.D) {
decodeBoxesWithParentData(ctx, d, &trafBox{})
},
// Movie Fragment Header
"mfhd": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldU32("sequence_number")
},
// Track Fragment Header
"tfhd": func(ctx *decodeContext, d *decode.D) {
d.FieldU8("version")
baseDataOffsetPresent := false
sampleDescriptionIndexPresent := false
defaultSampleDurationPresent := false
defaultSampleSizePresent := false
defaultSampleFlagsPresent := false
d.FieldStruct("flags", func(d *decode.D) {
d.FieldU7("unused0")
d.FieldBool("duration_is_empty")
d.FieldU10("unused1")
defaultSampleFlagsPresent = d.FieldBool("default_sample_flags_present")
defaultSampleSizePresent = d.FieldBool("default_sample_size_present")
defaultSampleDurationPresent = d.FieldBool("default_sample_duration_present")
d.FieldU1("unused2")
sampleDescriptionIndexPresent = d.FieldBool("sample_description_index_present")
baseDataOffsetPresent = d.FieldBool("base_data_offset_present")
})
trackID := int(d.FieldU32("track_id"))
m := &moof{}
if mb := ctx.currentMoofBox(); mb != nil {
m.offset = mb.offset
}
baseDataOffset := int64(0)
if baseDataOffsetPresent {
baseDataOffset = int64(d.FieldU64("base_data_offset"))
}
if sampleDescriptionIndexPresent {
m.defaultSampleDescriptionIndex = int(d.FieldU32("sample_description_index"))
}
if defaultSampleDurationPresent {
d.FieldU32("default_sample_duration")
}
if defaultSampleSizePresent {
m.defaultSampleSize = int64(d.FieldU32("default_sample_size"))
}
if defaultSampleFlagsPresent {
d.FieldU32("default_sample_flags")
}
if t := ctx.currentTrafBox(); t != nil {
t.trackID = trackID
t.moof = m
t.baseDataOffset = baseDataOffset
}
if t := ctx.currentTrack(); t != nil {
t.moofs = append(t.moofs, m)
}
},
// Track Fragment Run
"trun": func(ctx *decodeContext, d *decode.D) {
m := &moof{}
if t := ctx.currentTrafBox(); t != nil {
m = t.moof
}
d.FieldU8("version")
sampleCompositionTimeOffsetsPresent := false
sampleFlagsPresent := false
sampleSizePresent := false
sampleDurationPresent := false
firstSampleFlagsPresent := false
dataOffsetPresent := false
d.FieldStruct("flags", func(d *decode.D) {
d.FieldU12("unused0")
sampleCompositionTimeOffsetsPresent = d.FieldBool("sample_composition_time_offsets_present")
sampleFlagsPresent = d.FieldBool("sample_flags_present")
sampleSizePresent = d.FieldBool("sample_size_present")
sampleDurationPresent = d.FieldBool("sample_duration_present")
d.FieldU5("unused1")
firstSampleFlagsPresent = d.FieldBool("first_sample_flags_present")
d.FieldU1("unused2")
dataOffsetPresent = d.FieldBool("data_offset_present")
})
sampleCount := d.FieldU32("sample_count")
dataOffset := int64(0)
if dataOffsetPresent {
dataOffset = d.FieldS32("data_offset")
}
if firstSampleFlagsPresent {
d.FieldU32("first_sample_flags")
}
if sampleCount > maxSampleEntryCount {
d.Errorf("too many sample trun entries %d > %d", sampleCount, maxSampleEntryCount)
}
t := trun{
dataOffset: dataOffset,
}
d.FieldArray("samples", func(d *decode.D) {
for i := uint64(0); i < sampleCount; i++ {
sampleSize := m.defaultSampleSize
d.FieldStruct("sample", func(d *decode.D) {
if sampleDurationPresent {
d.FieldU32("sample_duration")
}
if sampleSizePresent {
sampleSize = int64(d.FieldU32("sample_size"))
}
if sampleFlagsPresent {
d.FieldU32("sample_flags")
}
if sampleCompositionTimeOffsetsPresent {
d.FieldU32("sample_composition_time_offset")
}
})
t.samplesSizes = append(t.samplesSizes, sampleSize)
}
})
m.truns = append(m.truns, t)
},
"tfdt": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
if version == 1 {
d.FieldU64("start_time")
} else {
d.FieldU32("start_time")
}
},
"mvex": decodeBoxes,
"trex": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldU32("track_id")
d.FieldU32("default_sample_description_index")
d.FieldU32("default_sample_duration")
d.FieldU32("default_sample_size")
d.FieldU4("reserved0")
d.FieldU2("is_leading")
d.FieldU2("sample_depends_on")
d.FieldU2("sample_is_depended_on")
d.FieldU2("sample_has_redundancy")
d.FieldU3("sample_padding_value")
d.FieldU1("sample_is_non_sync_sample")
d.FieldU16("sample_degradation_priority")
},
"mfra": decodeBoxes,
"tfra": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
d.FieldU32("track_id")
d.FieldU26("reserved")
lengthSizeOfTrafNum := d.FieldU2("length_size_of_traf_num")
sampleLengthSizeOfTrunNum := d.FieldU2("sample_length_size_of_trun_num")
lengthSizeOfSampleNum := d.FieldU2("length_size_of_sample_num")
entryCount := d.FieldU32("entry_count")
d.FieldArray("entries", func(d *decode.D) {
for i := uint64(0); i < entryCount; i++ {
d.FieldStruct("entry", func(d *decode.D) {
if version == 1 {
d.FieldU64("time")
d.FieldU64("moof_offset")
} else {
d.FieldU32("time")
d.FieldU32("moof_offset")
}
d.FieldU("traf_number", int(lengthSizeOfTrafNum+1)*8)
d.FieldU("trun_number", int(sampleLengthSizeOfTrunNum+1)*8)
d.FieldU("sample_number", int(lengthSizeOfSampleNum+1)*8)
})
}
})
},
"mfro": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldU32("mfra_size")
},
// TODO: item location
// HEIC image
"iloc": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
offsetSize := d.FieldU4("offset_size")
lengthSize := d.FieldU4("length_size")
baseOffsetSize := d.FieldU4("base_offset_size")
var indexSize uint64
switch version {
case 1, 2:
indexSize = d.FieldU4("index_size")
default:
d.FieldU4("reserved")
}
var itemCount uint64
if version < 2 {
itemCount = d.FieldU16("item_count")
} else {
itemCount = d.FieldU32("item_count")
}
d.FieldArray("items", func(d *decode.D) {
for i := uint64(0); i < itemCount; i++ {
d.FieldStruct("item", func(d *decode.D) {
switch version {
case 0, 1:
d.FieldU16("id")
case 2:
d.FieldU32("id")
}
switch version {
case 1, 2:
d.FieldU12("reserved")
d.FieldU4("construction_method")
}
d.FieldU16("data_reference_index")
d.FieldU("base_offset", int(baseOffsetSize)*8)
extentCount := d.FieldU16("extent_count")
d.FieldArray("extends", func(d *decode.D) {
for i := uint64(0); i < extentCount; i++ {
d.FieldStruct("extent", func(d *decode.D) {
if (version == 1 || version == 2) && indexSize > 0 {
d.FieldU("index", int(offsetSize)*8)
}
d.FieldU("offset", int(offsetSize)*8)
d.FieldU("length", int(lengthSize)*8)
})
}
})
})
}
})
},
"infe": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldU16("id")
d.FieldU16("protection_index")
d.FieldUTF8Null("item_name")
// TODO: really optional? seems so
if d.NotEnd() {
d.FieldUTF8Null("content_type")
}
if d.NotEnd() {
d.FieldUTF8Null("content_encoding")
}
},
"iinf": func(ctx *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
if version == 0 {
_ = d.FieldU16("entry_count")
decodeBoxes(ctx, d)
} else {
d.FieldRawLen("data", d.BitsLeft())
}
},
"iprp": decodeBoxes,
"ipco": decodeBoxes,
"ID32": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldU1("pad")
// ISO-639-2/T as 3*5 bit integers - 0x60
d.FieldStrFn("language", func(d *decode.D) string {
s := ""
for i := 0; i < 3; i++ {
s += fmt.Sprintf("%c", int(d.U5())+0x60)
}
return s
})
d.FieldFormat("data", id3v2Format, nil)
},
"mehd": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
switch version {
case 0:
d.FieldU32("fragment_duration")
case 1:
d.FieldU64("fragment_duration")
}
},
"pssh": func(_ *decodeContext, d *decode.D) {
var (
systemIDCommon = [16]byte{0x10, 0x77, 0xef, 0xec, 0xc0, 0xb2, 0x4d, 0x02, 0xac, 0xe3, 0x3c, 0x1e, 0x52, 0xe2, 0xfb, 0x4b}
systemIDWidevine = [16]byte{0xed, 0xef, 0x8b, 0xa9, 0x79, 0xd6, 0x4a, 0xce, 0xa3, 0xc8, 0x27, 0xdc, 0xd5, 0x1d, 0x21, 0xed}
systemIDPlayReady = [16]byte{0x9a, 0x04, 0xf0, 0x79, 0x98, 0x40, 0x42, 0x86, 0xab, 0x92, 0xe6, 0x5b, 0xe0, 0x88, 0x5f, 0x95}
systemIDFairPlay = [16]byte{0x94, 0xce, 0x86, 0xfb, 0x07, 0xff, 0x4f, 0x43, 0xad, 0xb8, 0x93, 0xd2, 0xfa, 0x96, 0x8c, 0xa2}
)
systemIDNames := scalar.BytesToScalar{
{Bytes: systemIDCommon[:], Scalar: scalar.S{Sym: "common"}},
{Bytes: systemIDWidevine[:], Scalar: scalar.S{Sym: "widevine"}},
{Bytes: systemIDPlayReady[:], Scalar: scalar.S{Sym: "playready"}},
{Bytes: systemIDFairPlay[:], Scalar: scalar.S{Sym: "fairplay"}},
}
version := d.FieldU8("version")
d.FieldU24("flags")
systemIDBR := d.FieldRawLen("system_id", 16*8, systemIDNames)
// TODO: make nicer
systemID := d.ReadAllBits(systemIDBR)
switch version {
case 0:
case 1:
kidCount := d.FieldU32("kid_count")
d.FieldArray("kids", func(d *decode.D) {
for i := uint64(0); i < kidCount; i++ {
d.FieldRawLen("kid", 16*8)
}
})
}
dataLen := d.FieldU32("data_size")
switch {
case bytes.Equal(systemID, systemIDWidevine[:]):
d.FieldFormatLen("data", int64(dataLen)*8, protoBufWidevineFormat, nil)
case bytes.Equal(systemID, systemIDPlayReady[:]):
d.FieldFormatLen("data", int64(dataLen)*8, psshPlayreadyFormat, nil)
case systemID == nil:
fallthrough
default:
d.FieldRawLen("data", int64(dataLen)*8)
}
},
"sinf": decodeBoxes,
"frma": func(ctx *decodeContext, d *decode.D) {
format := d.FieldUTF8("format", 4)
// set to original data format
// TODO: how to handle multiple descriptors? track current?
if t := ctx.currentTrack(); t != nil && len(t.sampleDescriptions) > 0 {
t.sampleDescriptions[0].originalFormat = format
}
},
"schm": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldUTF8("encryption_type", 4)
d.FieldU16("encryption_version")
if d.BitsLeft() > 0 {
d.FieldUTF8("uri", int(d.BitsLeft())/8)
}
},
"schi": decodeBoxes,
"btrt": func(_ *decodeContext, d *decode.D) {
d.FieldU32("decoding_buffer_size")
d.FieldU32("max_bitrate")
d.FieldU32("avg_bitrate")
},
"pasp": func(_ *decodeContext, d *decode.D) {
d.FieldU32("h_spacing")
d.FieldU32("v_spacing")
},
"uuid": func(_ *decodeContext, d *decode.D) {
d.FieldRawLen("uuid", 16*8, scalar.RawUUID, uuidNames)
d.FieldRawLen("data", d.BitsLeft())
},
"keys": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
entryCount := d.FieldU32("entry_count")
d.FieldArray("entries", func(d *decode.D) {
for i := uint64(0); i < entryCount; i++ {
d.FieldStruct("entry", func(d *decode.D) {
keySize := d.FieldU32("key_size")
d.FieldUTF8("key_namespace", 4)
d.FieldUTF8("key_name", int(keySize)-8)
})
}
})
},
"wave": decodeBoxes,
"saiz": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
flags := d.FieldU24("flags")
if flags&0b1 != 0 {
d.FieldU32("aux_info_type")
d.FieldU32("aux_info_type_parameter")
}
defaultSampleInfoSize := d.FieldU8("default_sample_info_size")
sampleCount := d.FieldU32("sample_count")
if defaultSampleInfoSize == 0 {
d.FieldArray("sample_size_info_table", func(d *decode.D) {
for i := uint64(0); i < sampleCount; i++ {
d.FieldU8("sample_size")
}
})
}
},
"sgpd": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
d.FieldU32("grouping_type")
var defaultLength uint64
if version == 1 {
defaultLength = d.FieldU32("default_length")
}
if version >= 2 {
d.FieldU32("default_sample_description_index")
}
entryCount := d.FieldU32("entry_count")
d.FieldArray("entries", func(d *decode.D) {
for i := uint64(0); i < entryCount; i++ {
entryLen := defaultLength
if version == 1 {
if defaultLength == 0 {
entryLen = d.FieldU32("description_length")
} else if entryLen == 0 {
d.Fatalf("sgpd groups entry len <= 0 version 1")
}
} else if entryLen == 0 {
d.Fatalf("sgpd groups entry len <= 0")
}
d.FieldRawLen("data", int64(entryLen)*8)
}
})
},
"sbgp": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
d.FieldU32("grouping_type")
if version == 1 {
d.FieldU32("grouping_type_parameter")
}
entryCount := d.FieldU32("entry_count")
d.FieldArray("entries", func(d *decode.D) {
for i := uint64(0); i < entryCount; i++ {
d.FieldStruct("entry", func(d *decode.D) {
d.FieldU32("sample_count")
d.FieldU32("group_description_index")
})
}
})
},
"saio": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
flags := d.FieldU24("flags")
if flags&0b1 != 0 {
d.FieldU32("aux_info_type")
d.FieldU32("aux_info_type_parameter")
}
entryCount := d.FieldU32("entry_count")
d.FieldArray("entries", func(d *decode.D) {
for i := uint64(0); i < entryCount; i++ {
if version == 0 {
d.FieldU32("offset")
} else {
d.FieldU64("offset")
}
}
})
},
"senc": func(ctx *decodeContext, d *decode.D) {
d.FieldU8("version")
flags := d.FieldU24("flags")
t := ctx.currentTrack()
if t == nil {
// need to know iv size
return
}
m := &moof{}
if t := ctx.currentTrafBox(); t != nil {
m = t.moof
}
s := senc{}
sampleCount := d.FieldU32("sample_count")
d.FieldArray("samples", func(d *decode.D) {
for i := uint64(0); i < sampleCount; i++ {
d.FieldStruct("entry", func(d *decode.D) {
if t.defaultIVSize != 0 {
d.FieldRawLen("iv", int64(t.defaultIVSize*8))
}
if flags&0b10 != 0 {
subSampleCount := d.FieldU16("subsample_count")
d.FieldArray("subsamples", func(d *decode.D) {
for i := uint64(0); i < subSampleCount; i++ {
d.FieldStruct("entry", func(d *decode.D) {
d.FieldU16("bytes_of_clean_data")
d.FieldU32("bytes_of_encrypted_data")
})
}
})
}
})
// TODO: add iv etc
s.entries = append(s.entries, struct{}{})
}
})
m.sencs = append(m.sencs, s)
},
"tenc": func(ctx *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
d.FieldU8("reserved0")
switch version {
case 0:
d.FieldU8("reserved1")
default:
d.FieldU4("default_crypto_bytes")
d.FieldU4("default_skip_bytes")
}
defaultIsEncrypted := d.FieldU8("default_is_encrypted")
defaultIVSize := d.FieldU8("default_iv_size")
d.FieldRawLen("default_kid", 8*16)
if defaultIsEncrypted != 0 && defaultIVSize == 0 {
defaultConstantIVSize := d.FieldU8("default_constant_iv_size")
d.FieldRawLen("default_constant_iv", int64(defaultConstantIVSize)*8)
}
if t := ctx.currentTrack(); t != nil {
t.defaultIVSize = int(defaultIVSize)
}
},
"covr": decodeBoxes,
"dec3": func(_ *decodeContext, d *decode.D) {
d.FieldU13("data_rate")
d.FieldU3("num_ind_sub")
d.FieldU2("fscod")
d.FieldU5("bsid")
d.FieldU5("bsmod")
d.FieldU3("acmod")
d.FieldU1("lfeon")
d.FieldU3("reserved0")
numDepSub := d.FieldU4("num_dep_sub")
if numDepSub > 0 {
d.FieldU9("chan_loc")
} else {
d.FieldU1("reserved1")
}
if d.BitsLeft() >= 16 {
d.FieldU7("reserved2")
ec3JocFlag := d.FieldBool("ec3_job_flag")
if ec3JocFlag {
d.FieldU1("ec3_job_complexity")
}
}
},
"dac4": func(_ *decodeContext, d *decode.D) {
d.FieldU3("ac4_dsi_version")
bitstreamVersion := d.FieldU7("bitstream_version")
d.FieldU1("fs_index")
d.FieldU4("frame_rate_index")
d.FieldU9("n_presentation")
if bitstreamVersion > 1 {
hasProgramID := d.FieldBool("has_program_id")
if hasProgramID {
d.FieldU16("short_program_id")
hasUUID := d.FieldBool("has_uuid")
if hasUUID {
d.FieldRawLen("uuid", 16*8)
}
}
}
// if ac4DsiVersion == 1 {
// d.FieldU2("bit_rate_mode")
// d.FieldU32("bit_rate")
// d.FieldU32("bit_rate_precision")
// }
// if ac4DsiVersion == 1 {
// d.FieldArray("presentations", func(d *decode.D) {
// for i := uint64(0); i < nPresentation; i++ {
// d.FieldStruct("presentation", func(d *decode.D) {
// d.FieldU8("presentation_version")
// presBytes := d.FieldUFn("pres_bytes", func() (uint64, decode.DisplayFormat, string) {
// n := d.U8()
// if n == 0x0ff {
// n += d.U16()
// }
// return n, decode.NumberDecimal, ""
// })
// d.FieldRawLen("data", int64(presBytes)*8)
// })
// }
// })
// }
if d.BitsLeft() > 0 {
d.FieldRawLen("data", d.BitsLeft())
}
},
"tapt": decodeBoxes,
"clef": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldFP32("width")
d.FieldFP32("height")
},
"prof": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldFP32("width")
d.FieldFP32("height")
},
"enof": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldFP32("width")
d.FieldFP32("height")
},
"clap": func(_ *decodeContext, d *decode.D) {
d.FieldU32("aperture_width_n")
d.FieldU32("aperture_width_d")
d.FieldU32("aperture_height_n")
d.FieldU32("aperture_height_d")
d.FieldU32("horiz_off_n")
d.FieldU32("horiz_off_d")
d.FieldU32("vert_off_n")
d.FieldU32("vert_off_d")
},
"smhd": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldFP16("balance")
d.FieldU16("reserved")
},
"colr": func(_ *decodeContext, d *decode.D) {
parameterType := d.FieldUTF8("parameter_type", 4)
switch parameterType {
case "nclx", "nclc":
d.FieldU16("primaries_index", format.ISO_23091_2_ColourPrimariesMap)
d.FieldU16("transfer_function_index", format.ISO_23091_2_TransferCharacteristicMap)
d.FieldU16("matrix_index", format.ISO_23091_2_MatrixCoefficients)
switch parameterType {
case "nclx":
d.FieldU8("color_range")
}
case "prof":
d.FieldFormat("profile", iccProfileFormat, nil)
default:
d.FieldRawLen("data", d.BitsLeft())
}
},
"ispe": func(_ *decodeContext, d *decode.D) {
d.FieldU8("version")
d.FieldU24("flags")
d.FieldU32("image_width")
d.FieldU32("image_height")
},
"ipma": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
flags := d.FieldU24("flags")
entryCount := d.FieldU32("entry_count")
d.FieldArray("entries", func(d *decode.D) {
for i := uint64(0); i < entryCount; i++ {
d.FieldStruct("entry", func(d *decode.D) {
if version < 1 {
d.FieldU16("item_id")
} else {
d.FieldU32("item_id")
}
associationCount := d.FieldU8("association_count")
d.FieldArray("associations", func(d *decode.D) {
for j := uint64(0); j < associationCount; j++ {
d.FieldStruct("association", func(d *decode.D) {
d.FieldBool("essential")
if flags&0b1 != 0 {
d.FieldU15("property_index")
} else {
d.FieldU7("item_id")
}
})
}
})
})
}
})
},
"pitm": func(_ *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
if version < 1 {
d.FieldU16("item_id")
} else {
d.FieldU32("item_id")
}
},
"iref": func(ctx *decodeContext, d *decode.D) {
version := d.FieldU8("version")
d.FieldU24("flags")
decodeBoxesWithParentData(ctx, d, &irefBox{version: int(version)})
},
"dimg": irefEntryDecode,
"thmb": irefEntryDecode,
"cdsc": irefEntryDecode,
"irot": func(_ *decodeContext, d *decode.D) {
d.FieldU8("rotation", scalar.UToSymU{
0: 0,
1: 90,
2: 180,
3: 270,
})
},
}
}