commit 3d5f8eb4010819a69e7efd1819dd4047fbdc8aa1
parent aadc796754a404c64562bb2061bc0085e645e6c6
Author: Oliver Lowe <o@olowe.co>
Date: Tue, 7 May 2024 13:21:21 +1000
internal/scte35: remove more unused types
PrivateDescriptor is implemented with the SpliceDescriptor type.
SpliceInfoSection is replaced with SpliceInfo.
Diffstat:
4 files changed, 0 insertions(+), 417 deletions(-)
diff --git a/internal/scte35/private_descriptor.go b/internal/scte35/private_descriptor.go
@@ -1,82 +0,0 @@
-// Copyright 2021 Comcast Cable Communications Management, LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package scte35
-
-import (
- "encoding/binary"
- "fmt"
-
- "github.com/bamiaux/iobit"
-)
-
-// PrivateDescriptor encapsulates the contents of non-CUEI descriptors
-type PrivateDescriptor struct {
- PrivateTag uint32
- Identifier uint32
- PrivateBytes Bytes
-}
-
-// IdentifierString returns the identifier as a string
-func (sd *PrivateDescriptor) IdentifierString() string {
- b := make([]byte, 4)
- binary.BigEndian.PutUint32(b, sd.Identifier)
- return string(b)
-}
-
-// Tag returns the splice_descriptor_tag.
-func (sd *PrivateDescriptor) Tag() uint32 { return sd.PrivateTag }
-
-// decode updates this splice_descriptor from binary.
-func (sd *PrivateDescriptor) decode(b []byte) error {
- r := iobit.NewReader(b)
-
- sd.PrivateTag = r.Uint32(8)
- r.Skip(8) // descriptor_length
- sd.Identifier = r.Uint32(32)
- sd.PrivateBytes = r.LeftBytes()
- // LeftBytes doesnt advance position
- r.Skip(uint(len(sd.PrivateBytes) * 8))
-
- if err := readerError(r); err != nil {
- return fmt.Errorf("private_descriptor: %w", err)
- }
- return nil
-}
-
-// encode this splice_descriptor to binary.
-func (sd *PrivateDescriptor) encode() ([]byte, error) {
- length := sd.length()
-
- // add 2 bytes to contain splice_descriptor_tag & descriptor_length
- buf := make([]byte, length+2)
- iow := iobit.NewWriter(buf)
- iow.PutUint32(8, sd.PrivateTag)
- iow.PutUint32(8, uint32(length))
- iow.PutUint32(32, sd.Identifier)
- _, err := iow.Write(sd.PrivateBytes)
- if err != nil {
- return buf, err
- }
- return buf, iow.Flush()
-}
-
-// descriptorLength returns the descriptor_length
-func (sd *PrivateDescriptor) length() int {
- length := 32 // identifier
- length += len(sd.PrivateBytes) * 8 // private_bytes
- return length / 8
-}
diff --git a/internal/scte35/scte35.go b/internal/scte35/scte35.go
@@ -19,7 +19,6 @@
package scte35
import (
- "encoding/hex"
"errors"
"math"
"time"
@@ -93,25 +92,6 @@ func TicksToDuration(ticks uint64) time.Duration {
return time.Duration(int64(s * float64(time.Second)))
}
-// Bytes is a byte array.
-type Bytes []byte
-
-// MarshalText encodes Bytes to a hexadecimal string.
-func (bb Bytes) MarshalText() ([]byte, error) {
- tmp := hex.EncodeToString(bb)
- return []byte(tmp), nil
-}
-
-// UnmarshalText decodes a hexadecimal string.
-func (bb *Bytes) UnmarshalText(b []byte) error {
- tmp, err := hex.DecodeString(string(b))
- if err != nil {
- return err
- }
- *bb = tmp
- return nil
-}
-
// readerError returns the readers error state, if any.
func readerError(r iobit.Reader) error {
if r.LeftBits() > 0 {
diff --git a/internal/scte35/splice_info_section.go b/internal/scte35/splice_info_section.go
@@ -1,289 +0,0 @@
-// Copyright 2021 Comcast Cable Communications Management, LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package scte35
-
-/*
-import (
- "encoding/base64"
- "encoding/hex"
- "fmt"
- "time"
-
- "github.com/bamiaux/iobit"
-)
-
-const (
- // TableID is an 8-bit field that shall be 0xFC.
- TableID = 0xFC
- // SectionSyntaxIndicator is a 1-bit field that should always be set to '0'.
- SectionSyntaxIndicator = false
- // PrivateIndicator is a 1-bit flag that shall be set to 0.
- PrivateIndicator = false
-)
-
-const (
- // SAPType1 indicates closed GOP with no leading pictures.
- SAPType1 uint32 = iota
- // SAPType2 indicates closed GOP with leading pictures.
- SAPType2
- // SAPType3 indicates Open GOP.
- SAPType3
- // SAPTypeNotSpecified indicates the type of SAP, if any, is not signaled.
- SAPTypeNotSpecified
-)
-
-// SpliceInfoSection shall be carried in transport packets whereby only one
-// section or partial section may be in any transport packet.
-// Splice_info_sections shall always start at the beginning of a transport
-// packet payload. When a section begins in a transport packet and this is the
-// first packet of the splice_info_section, the pointer_field shall be present
-// and equal to 0x00 and the payload_unit_start_indicator bit shall be equal to
-// one (per the requirements of section syntax usage per [MPEG Systems]).
-type SpliceInfoSection struct {
- EncryptedPacket EncryptedPacket
- SpliceCommand *Command
- SpliceDescriptors SpliceDescriptors
- SAPType uint32
- PreRollMilliSeconds uint32 // no corresponding binary field
- PTSAdjustment uint64
- ProtocolVersion uint32
- Tier uint32
- alignmentStuffing []byte // alignment_stuffing
- ecrc32 []byte // decoded e_crc_32
- crc32 []byte // decoded crc_32
-}
-
-// Base64 returns the SpliceInfoSection as a base64 encoded string.
-func (sis *SpliceInfoSection) Base64() string {
- b, err := sis.Encode()
- if err != nil {
- Logger.Printf("Error encoding splice_info_section: %s\n", err)
- return ""
- }
- return base64.StdEncoding.EncodeToString(b)
-}
-
-// Decode the contents of a byte array into this SpliceInfoSection.
-func (sis *SpliceInfoSection) Decode(b []byte) (err error) {
- r := iobit.NewReader(b)
- r.Skip(8) // table_id (shall be 0xFC)
- r.Skip(1) // section_syntax_indicator (shall be 0)
- r.Skip(1) // private_indicator (shall be 0)
- sis.SAPType = r.Uint32(2)
- r.Skip(12) // section_length (informative, can ignore)
-
- sis.ProtocolVersion = r.Uint32(8)
- encryptedPacket := r.Bit()
- sis.EncryptedPacket.EncryptionAlgorithm = r.Uint32(6)
- sis.PTSAdjustment = r.Uint64(33)
- sis.EncryptedPacket.CWIndex = r.Uint32(8)
- sis.Tier = r.Uint32(12)
-
- spliceCommandLength := int(r.Uint32(12)) // in bytes
- //spliceCommandType := r.Uint32(8)
- switch spliceCommandLength {
- case 0xFFF:
- // legacy signal, decode and skip (buffer underflow expected here)
- //r2 := r.Peek()
- sis.SpliceCommand, err = decodeSpliceCommand(spliceCommandType, r2.LeftBytes())
- if err != nil && !errors.Is(err, ErrBufferUnderflow) {
- return err
- }
- //r.Skip(uint(sis.SpliceCommand.length() * 8))
- default:
- // standard signal, decode as usual
- sis.SpliceCommand, err = decodeSpliceCommand(spliceCommandType, r.Bytes(spliceCommandLength))
- if err != nil {
- return err
- }
- }
-
- descriptorLoopLength := int(r.Uint32(16)) // bytes
- sis.SpliceDescriptors, err = decodeSpliceDescriptors(r.Bytes(descriptorLoopLength))
- if err != nil {
- return err
- }
-
- if encryptedPacket {
- stuffedBytes := (int(r.LeftBits()) - 64) / 8
- if stuffedBytes > 0 {
- sis.alignmentStuffing = r.Bytes(stuffedBytes)
- }
- sis.ecrc32 = r.Bytes(4)
- } else {
- stuffedBytes := (int(r.LeftBits()) - 32) / 8
- if stuffedBytes > 0 {
- sis.alignmentStuffing = r.Bytes(stuffedBytes)
- }
- }
- sis.crc32 = r.Bytes(4)
-
- if err := readerError(r); err != nil {
- return fmt.Errorf("splice_info_section: %w", err)
- }
-
- if err = verifyCRC32(b); err != nil {
- return fmt.Errorf("splice_info_section: %w", err)
- }
-
- return nil
-}
-
-// Duration attempts to return the duration of the signal.
-func (sis *SpliceInfoSection) Duration() time.Duration {
- // if this is a splice insert with a duration, use it
- if sis.SpliceCommand == nil {
- return 0
- }
- if sis.SpliceCommand == CommandSpliceInsert {
-
- if sc, ok := sis.SpliceCommand.(*SpliceInsert); ok {
- if sc.BreakDuration != nil {
- return TicksToDuration(sc.BreakDuration.Duration)
- }
- }
-
- ticks := uint64(0)
- for _, sd := range sis.SpliceDescriptors {
- if sdt, ok := sd.(*SegmentationDescriptor); ok {
- if sdt.SegmentationDuration != nil {
- ticks += *sdt.SegmentationDuration
- }
- }
- }
- return TicksToDuration(ticks)
-}
-
-// Encode returns the binary representation of this SpliceInfoSection as a
-// byte array.
-func (sis *SpliceInfoSection) Encode() ([]byte, error) {
- buf := make([]byte, sis.length())
-
- iow := iobit.NewWriter(buf)
- iow.PutUint32(8, TableID)
- iow.PutBit(SectionSyntaxIndicator)
- iow.PutBit(PrivateIndicator)
- iow.PutUint32(2, sis.SAPType)
- iow.PutUint32(12, uint32(sis.sectionLength()))
- iow.PutUint32(8, sis.ProtocolVersion)
-
- iow.PutBit(sis.EncryptedPacketFlag())
- iow.PutUint32(6, sis.EncryptedPacket.EncryptionAlgorithm)
- iow.PutUint64(33, sis.PTSAdjustment)
- iow.PutUint32(8, sis.EncryptedPacket.CWIndex)
- iow.PutUint32(12, sis.Tier)
-
- if sis.SpliceCommand != nil {
- b, err := encodeCommand(sis.SpliceCommand)
- if err != nil {
- return buf, fmt.Errorf("encode command: %w", err)
- }
- for _, bb := range b {
- iow.PutByte(bb)
- }
- }
- iow.PutUint32(16, uint32(sis.descriptorLoopLength()))
- for _, sd := range sis.SpliceDescriptors {
- sde, err := sd.encode()
- if err != nil {
- return buf, err
- }
- if _, err = iow.Write(sde); err != nil {
- return buf, err
- }
- }
-
- // alignment_stuffing
- _, _ = iow.Write(sis.alignmentStuffing)
-
- // Encoding encrypted signals is untested.
- if sis.EncryptedPacket.EncryptionAlgorithm != EncryptionAlgorithmNone {
- iow.PutUint32(32, calculateCRC32(buf[:iow.Index()/8])) // E_CRC_32
- }
-
- // Re-calculate CRC_32 to ensure correctness
- iow.PutUint32(32, calculateCRC32(buf[:iow.Index()/8])) // CRC_32
-
- return buf, iow.Flush()
-}
-
-// EncryptedPacketFlag returns the value of encrypted_packet_flag
-func (sis *SpliceInfoSection) EncryptedPacketFlag() bool {
- return sis.EncryptedPacket.EncryptionAlgorithm != EncryptionAlgorithmNone
-}
-
-// Hex returns the SpliceInfoSection as a hexadecimal encoded string.
-func (sis *SpliceInfoSection) Hex() string {
- b, err := sis.Encode()
- if err != nil {
- Logger.Printf("Error encoding splice_info_section: %s\n", err)
- return ""
- }
- return hex.EncodeToString(b)
-}
-
-// length returns the expected length of the encoded splice_info_section, in
-// bytes.
-func (sis *SpliceInfoSection) length() int {
- length := 8 // table_id
- length++ // section_syntax_indicator
- length++ // private_indicator
- length += 2 // reserved
- length += 12 // section_length (bytes remaining)
- length += sis.sectionLength() * 8 // everything else (bytes -> bits)
- return length / 8
-}
-
-// sectionLength returns the section_length, in bytes
-func (sis *SpliceInfoSection) sectionLength() int {
- length := 8 // protocol_version
- length++ // encrypted_packet
- length += 6 // encryption_algorithm
- length += 33 // pts_adjustment
- length += 8 // cw_index
- length += 12 // tier
- length += 12 // splice_command_length
- length += 8 // splice_command_type
- if sis.SpliceCommand != nil {
- // length += sis.SpliceCommand.length() * 8 // bytes -> bits
- }
- length += 16 // descriptor_loop_length (bytes remaining value)
- length += sis.descriptorLoopLength() * 8 // bytes -> bits
- length += len(sis.alignmentStuffing) * 8 // bytes -> bits
- // we don't officially support encrypted signals so this section is untested.
- // It's implemented here as a base-line if/when we decide to support
- // encryption (ie, use at your own risk)
- if sis.EncryptedPacket.EncryptionAlgorithm != EncryptionAlgorithmNone {
- length += 32 // ECRC_32
- }
-
- length += 32 // CRC_32
- return length / 8
-}
-
-// descriptorLoopLength return the descriptor_loop_length
-func (sis *SpliceInfoSection) descriptorLoopLength() int {
- length := 0
- for _, d := range sis.SpliceDescriptors {
- length += 8 // splice_descriptor_tag
- length += 8 // descriptor_length
- length += d.length() * 8 // splice_descriptor()
- }
- return length / 8
-}
-
-*/
-\ No newline at end of file
diff --git a/internal/scte35/splice_info_section_test.go b/internal/scte35/splice_info_section_test.go
@@ -1,25 +0,0 @@
-package scte35
-
-/*
-type sistest struct {
- name string
- sis SpliceInfoSection
-}
-
-var tsis SpliceInfoSection = SpliceInfoSection{
- Tier: uint32(4095),
- SAPType: SAPTypeNotSpecified,
- EncryptedPacket: EncryptedPacket{CWIndex: 255},
- SpliceCommand: &Command{
- Type: SpliceSchedule,
- Schedule: []Event{
- Event{
- ID: 12345,
- Cancel: true,
- OutOfNetwork: true,
- BreakDuration: &BreakDuration{true, 9876543},
- },
- },
- },
-}
-*/
