mirror of
1
Fork 0
gotosocial/vendor/github.com/abema/go-mp4/marshaller.go

664 lines
14 KiB
Go

package mp4
import (
"bytes"
"errors"
"fmt"
"io"
"math"
"reflect"
"github.com/abema/go-mp4/internal/bitio"
)
const (
anyVersion = math.MaxUint8
)
var ErrUnsupportedBoxVersion = errors.New("unsupported box version")
func readerHasSize(reader bitio.ReadSeeker, size uint64) bool {
pre, err := reader.Seek(0, io.SeekCurrent)
if err != nil {
return false
}
end, err := reader.Seek(0, io.SeekEnd)
if err != nil {
return false
}
if uint64(end-pre) < size {
return false
}
_, err = reader.Seek(pre, io.SeekStart)
if err != nil {
return false
}
return true
}
type marshaller struct {
writer bitio.Writer
wbits uint64
src IImmutableBox
ctx Context
}
func Marshal(w io.Writer, src IImmutableBox, ctx Context) (n uint64, err error) {
boxDef := src.GetType().getBoxDef(ctx)
if boxDef == nil {
return 0, ErrBoxInfoNotFound
}
v := reflect.ValueOf(src).Elem()
m := &marshaller{
writer: bitio.NewWriter(w),
src: src,
ctx: ctx,
}
if err := m.marshalStruct(v, boxDef.fields); err != nil {
return 0, err
}
if m.wbits%8 != 0 {
return 0, fmt.Errorf("box size is not multiple of 8 bits: type=%s, bits=%d", src.GetType().String(), m.wbits)
}
return m.wbits / 8, nil
}
func (m *marshaller) marshal(v reflect.Value, fi *fieldInstance) error {
switch v.Type().Kind() {
case reflect.Ptr:
return m.marshalPtr(v, fi)
case reflect.Struct:
return m.marshalStruct(v, fi.children)
case reflect.Array:
return m.marshalArray(v, fi)
case reflect.Slice:
return m.marshalSlice(v, fi)
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return m.marshalInt(v, fi)
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return m.marshalUint(v, fi)
case reflect.Bool:
return m.marshalBool(v, fi)
case reflect.String:
return m.marshalString(v)
default:
return fmt.Errorf("unsupported type: %s", v.Type().Kind())
}
}
func (m *marshaller) marshalPtr(v reflect.Value, fi *fieldInstance) error {
return m.marshal(v.Elem(), fi)
}
func (m *marshaller) marshalStruct(v reflect.Value, fs []*field) error {
for _, f := range fs {
fi := resolveFieldInstance(f, m.src, v, m.ctx)
if !isTargetField(m.src, fi, m.ctx) {
continue
}
wbits, override, err := fi.cfo.OnWriteField(f.name, m.writer, m.ctx)
if err != nil {
return err
}
m.wbits += wbits
if override {
continue
}
err = m.marshal(v.FieldByName(f.name), fi)
if err != nil {
return err
}
}
return nil
}
func (m *marshaller) marshalArray(v reflect.Value, fi *fieldInstance) error {
size := v.Type().Size()
for i := 0; i < int(size)/int(v.Type().Elem().Size()); i++ {
var err error
err = m.marshal(v.Index(i), fi)
if err != nil {
return err
}
}
return nil
}
func (m *marshaller) marshalSlice(v reflect.Value, fi *fieldInstance) error {
length := uint64(v.Len())
if fi.length != LengthUnlimited {
if length < uint64(fi.length) {
return fmt.Errorf("the slice has too few elements: required=%d actual=%d", fi.length, length)
}
length = uint64(fi.length)
}
elemType := v.Type().Elem()
if elemType.Kind() == reflect.Uint8 && fi.size == 8 && m.wbits%8 == 0 {
if _, err := io.CopyN(m.writer, bytes.NewBuffer(v.Bytes()), int64(length)); err != nil {
return err
}
m.wbits += length * 8
return nil
}
for i := 0; i < int(length); i++ {
m.marshal(v.Index(i), fi)
}
return nil
}
func (m *marshaller) marshalInt(v reflect.Value, fi *fieldInstance) error {
signed := v.Int()
if fi.is(fieldVarint) {
return errors.New("signed varint is unsupported")
}
signBit := signed < 0
val := uint64(signed)
for i := uint(0); i < fi.size; i += 8 {
v := val
size := uint(8)
if fi.size > i+8 {
v = v >> (fi.size - (i + 8))
} else if fi.size < i+8 {
size = fi.size - i
}
// set sign bit
if i == 0 {
if signBit {
v |= 0x1 << (size - 1)
} else {
v &= 0x1<<(size-1) - 1
}
}
if err := m.writer.WriteBits([]byte{byte(v)}, size); err != nil {
return err
}
m.wbits += uint64(size)
}
return nil
}
func (m *marshaller) marshalUint(v reflect.Value, fi *fieldInstance) error {
val := v.Uint()
if fi.is(fieldVarint) {
m.writeUvarint(val)
return nil
}
for i := uint(0); i < fi.size; i += 8 {
v := val
size := uint(8)
if fi.size > i+8 {
v = v >> (fi.size - (i + 8))
} else if fi.size < i+8 {
size = fi.size - i
}
if err := m.writer.WriteBits([]byte{byte(v)}, size); err != nil {
return err
}
m.wbits += uint64(size)
}
return nil
}
func (m *marshaller) marshalBool(v reflect.Value, fi *fieldInstance) error {
var val byte
if v.Bool() {
val = 0xff
} else {
val = 0x00
}
if err := m.writer.WriteBits([]byte{val}, fi.size); err != nil {
return err
}
m.wbits += uint64(fi.size)
return nil
}
func (m *marshaller) marshalString(v reflect.Value) error {
data := []byte(v.String())
for _, b := range data {
if err := m.writer.WriteBits([]byte{b}, 8); err != nil {
return err
}
m.wbits += 8
}
// null character
if err := m.writer.WriteBits([]byte{0x00}, 8); err != nil {
return err
}
m.wbits += 8
return nil
}
func (m *marshaller) writeUvarint(u uint64) error {
for i := 21; i > 0; i -= 7 {
if err := m.writer.WriteBits([]byte{(byte(u >> uint(i))) | 0x80}, 8); err != nil {
return err
}
m.wbits += 8
}
if err := m.writer.WriteBits([]byte{byte(u) & 0x7f}, 8); err != nil {
return err
}
m.wbits += 8
return nil
}
type unmarshaller struct {
reader bitio.ReadSeeker
dst IBox
size uint64
rbits uint64
ctx Context
}
func UnmarshalAny(r io.ReadSeeker, boxType BoxType, payloadSize uint64, ctx Context) (box IBox, n uint64, err error) {
dst, err := boxType.New(ctx)
if err != nil {
return nil, 0, err
}
n, err = Unmarshal(r, payloadSize, dst, ctx)
return dst, n, err
}
func Unmarshal(r io.ReadSeeker, payloadSize uint64, dst IBox, ctx Context) (n uint64, err error) {
boxDef := dst.GetType().getBoxDef(ctx)
if boxDef == nil {
return 0, ErrBoxInfoNotFound
}
v := reflect.ValueOf(dst).Elem()
dst.SetVersion(anyVersion)
u := &unmarshaller{
reader: bitio.NewReadSeeker(r),
dst: dst,
size: payloadSize,
ctx: ctx,
}
if n, override, err := dst.BeforeUnmarshal(r, payloadSize, u.ctx); err != nil {
return 0, err
} else if override {
return n, nil
} else {
u.rbits = n * 8
}
sn, err := r.Seek(0, io.SeekCurrent)
if err != nil {
return 0, err
}
if err := u.unmarshalStruct(v, boxDef.fields); err != nil {
if err == ErrUnsupportedBoxVersion {
r.Seek(sn, io.SeekStart)
}
return 0, err
}
if u.rbits%8 != 0 {
return 0, fmt.Errorf("box size is not multiple of 8 bits: type=%s, size=%d, bits=%d", dst.GetType().String(), u.size, u.rbits)
}
if u.rbits > u.size*8 {
return 0, fmt.Errorf("overrun error: type=%s, size=%d, bits=%d", dst.GetType().String(), u.size, u.rbits)
}
return u.rbits / 8, nil
}
func (u *unmarshaller) unmarshal(v reflect.Value, fi *fieldInstance) error {
var err error
switch v.Type().Kind() {
case reflect.Ptr:
err = u.unmarshalPtr(v, fi)
case reflect.Struct:
err = u.unmarshalStructInternal(v, fi)
case reflect.Array:
err = u.unmarshalArray(v, fi)
case reflect.Slice:
err = u.unmarshalSlice(v, fi)
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
err = u.unmarshalInt(v, fi)
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
err = u.unmarshalUint(v, fi)
case reflect.Bool:
err = u.unmarshalBool(v, fi)
case reflect.String:
err = u.unmarshalString(v, fi)
default:
return fmt.Errorf("unsupported type: %s", v.Type().Kind())
}
return err
}
func (u *unmarshaller) unmarshalPtr(v reflect.Value, fi *fieldInstance) error {
v.Set(reflect.New(v.Type().Elem()))
return u.unmarshal(v.Elem(), fi)
}
func (u *unmarshaller) unmarshalStructInternal(v reflect.Value, fi *fieldInstance) error {
if fi.size != 0 && fi.size%8 == 0 {
u2 := *u
u2.size = uint64(fi.size / 8)
u2.rbits = 0
if err := u2.unmarshalStruct(v, fi.children); err != nil {
return err
}
u.rbits += u2.rbits
if u2.rbits != uint64(fi.size) {
return errors.New("invalid alignment")
}
return nil
}
return u.unmarshalStruct(v, fi.children)
}
func (u *unmarshaller) unmarshalStruct(v reflect.Value, fs []*field) error {
for _, f := range fs {
fi := resolveFieldInstance(f, u.dst, v, u.ctx)
if !isTargetField(u.dst, fi, u.ctx) {
continue
}
rbits, override, err := fi.cfo.OnReadField(f.name, u.reader, u.size*8-u.rbits, u.ctx)
if err != nil {
return err
}
u.rbits += rbits
if override {
continue
}
err = u.unmarshal(v.FieldByName(f.name), fi)
if err != nil {
return err
}
if v.FieldByName(f.name).Type() == reflect.TypeOf(FullBox{}) && !u.dst.GetType().IsSupportedVersion(u.dst.GetVersion(), u.ctx) {
return ErrUnsupportedBoxVersion
}
}
return nil
}
func (u *unmarshaller) unmarshalArray(v reflect.Value, fi *fieldInstance) error {
size := v.Type().Size()
for i := 0; i < int(size)/int(v.Type().Elem().Size()); i++ {
var err error
err = u.unmarshal(v.Index(i), fi)
if err != nil {
return err
}
}
return nil
}
func (u *unmarshaller) unmarshalSlice(v reflect.Value, fi *fieldInstance) error {
var slice reflect.Value
elemType := v.Type().Elem()
length := uint64(fi.length)
if fi.length == LengthUnlimited {
if fi.size != 0 {
left := (u.size)*8 - u.rbits
if left%uint64(fi.size) != 0 {
return errors.New("invalid alignment")
}
length = left / uint64(fi.size)
} else {
length = 0
}
}
if u.rbits%8 == 0 && elemType.Kind() == reflect.Uint8 && fi.size == 8 {
totalSize := length * uint64(fi.size) / 8
if !readerHasSize(u.reader, totalSize) {
return fmt.Errorf("not enough bits")
}
buf := bytes.NewBuffer(make([]byte, 0, totalSize))
if _, err := io.CopyN(buf, u.reader, int64(totalSize)); err != nil {
return err
}
slice = reflect.ValueOf(buf.Bytes())
u.rbits += uint64(totalSize) * 8
} else {
slice = reflect.MakeSlice(v.Type(), 0, 0)
for i := 0; ; i++ {
if fi.length != LengthUnlimited && uint(i) >= fi.length {
break
}
if fi.length == LengthUnlimited && u.rbits >= u.size*8 {
break
}
slice = reflect.Append(slice, reflect.Zero(elemType))
if err := u.unmarshal(slice.Index(i), fi); err != nil {
return err
}
if u.rbits > u.size*8 {
return fmt.Errorf("failed to read array completely: fieldName=\"%s\"", fi.name)
}
}
}
v.Set(slice)
return nil
}
func (u *unmarshaller) unmarshalInt(v reflect.Value, fi *fieldInstance) error {
if fi.is(fieldVarint) {
return errors.New("signed varint is unsupported")
}
if fi.size == 0 {
return fmt.Errorf("size must not be zero: %s", fi.name)
}
data, err := u.reader.ReadBits(fi.size)
if err != nil {
return err
}
u.rbits += uint64(fi.size)
signBit := false
if len(data) > 0 {
signMask := byte(0x01) << ((fi.size - 1) % 8)
signBit = data[0]&signMask != 0
if signBit {
data[0] |= ^(signMask - 1)
}
}
var val uint64
if signBit {
val = ^uint64(0)
}
for i := range data {
val <<= 8
val |= uint64(data[i])
}
v.SetInt(int64(val))
return nil
}
func (u *unmarshaller) unmarshalUint(v reflect.Value, fi *fieldInstance) error {
if fi.is(fieldVarint) {
val, err := u.readUvarint()
if err != nil {
return err
}
v.SetUint(val)
return nil
}
if fi.size == 0 {
return fmt.Errorf("size must not be zero: %s", fi.name)
}
data, err := u.reader.ReadBits(fi.size)
if err != nil {
return err
}
u.rbits += uint64(fi.size)
val := uint64(0)
for i := range data {
val <<= 8
val |= uint64(data[i])
}
v.SetUint(val)
return nil
}
func (u *unmarshaller) unmarshalBool(v reflect.Value, fi *fieldInstance) error {
if fi.size == 0 {
return fmt.Errorf("size must not be zero: %s", fi.name)
}
data, err := u.reader.ReadBits(fi.size)
if err != nil {
return err
}
u.rbits += uint64(fi.size)
val := false
for _, b := range data {
val = val || (b != byte(0))
}
v.SetBool(val)
return nil
}
func (u *unmarshaller) unmarshalString(v reflect.Value, fi *fieldInstance) error {
switch fi.strType {
case stringType_C:
return u.unmarshalStringC(v)
case stringType_C_P:
return u.unmarshalStringCP(v, fi)
default:
return fmt.Errorf("unknown string type: %d", fi.strType)
}
}
func (u *unmarshaller) unmarshalStringC(v reflect.Value) error {
data := make([]byte, 0, 16)
for {
if u.rbits >= u.size*8 {
break
}
c, err := u.reader.ReadBits(8)
if err != nil {
return err
}
u.rbits += 8
if c[0] == 0 {
break // null character
}
data = append(data, c[0])
}
v.SetString(string(data))
return nil
}
func (u *unmarshaller) unmarshalStringCP(v reflect.Value, fi *fieldInstance) error {
if ok, err := u.tryReadPString(v, fi); err != nil {
return err
} else if ok {
return nil
}
return u.unmarshalStringC(v)
}
func (u *unmarshaller) tryReadPString(v reflect.Value, fi *fieldInstance) (ok bool, err error) {
remainingSize := (u.size*8 - u.rbits) / 8
if remainingSize < 2 {
return false, nil
}
offset, err := u.reader.Seek(0, io.SeekCurrent)
if err != nil {
return false, err
}
defer func() {
if err == nil && !ok {
_, err = u.reader.Seek(offset, io.SeekStart)
}
}()
buf0 := make([]byte, 1)
if _, err := io.ReadFull(u.reader, buf0); err != nil {
return false, err
}
remainingSize--
plen := buf0[0]
if uint64(plen) > remainingSize {
return false, nil
}
buf := make([]byte, int(plen))
if _, err := io.ReadFull(u.reader, buf); err != nil {
return false, err
}
remainingSize -= uint64(plen)
if fi.cfo.IsPString(fi.name, buf, remainingSize, u.ctx) {
u.rbits += uint64(len(buf)+1) * 8
v.SetString(string(buf))
return true, nil
}
return false, nil
}
func (u *unmarshaller) readUvarint() (uint64, error) {
var val uint64
for {
octet, err := u.reader.ReadBits(8)
if err != nil {
return 0, err
}
u.rbits += 8
val = (val << 7) + uint64(octet[0]&0x7f)
if octet[0]&0x80 == 0 {
return val, nil
}
}
}