streaming

commit dfd42b06d7b8816d35e0b574ad54e5146d9d5ab6
parent f9d860476fbcf68d9cb28f489eafc3db682a040c
Author: Oliver Lowe <o@olowe.co>
Date:   Wed,  8 May 2024 17:29:31 +1000

internal/scte35: use plain byte slices instead of iobit

Since all that was being done was reading a uint32 from a byte slice,
we can just use Go's encoding/binary instead of relying on some 3rd
party package. This removes the entire module's dependency on iobit!

Diffstat:
M
go.mod
 | 
5
-----
D
go.sum
 | 
4
----
M
internal/scte35/crc_32.go
 | 
14
+++++---------
M
internal/scte35/scte35.go
 | 
13
-------------

4 files changed, 5 insertions(+), 31 deletions(-)
diff --git a/go.mod b/go.mod
@@ -1,8 +1,3 @@
 module github.com/untangledco/streaming
 
 go 1.19
-
-require (
-	github.com/bamiaux/iobit v0.0.0-20170418073505-498159a04883
-	golang.org/x/text v0.14.0
-)
diff --git a/go.sum b/go.sum
@@ -1,4 +0,0 @@
-github.com/bamiaux/iobit v0.0.0-20170418073505-498159a04883 h1:XNtOMwxmV2PI/vuTHDZnFzGIFNUh8MK73q7+Kna7AXs=
-github.com/bamiaux/iobit v0.0.0-20170418073505-498159a04883/go.mod h1:9IjZnSQGh45J46HHS45pxuMJ6WFTtSXbaX0FoHDvxh8=
-golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
-golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
diff --git a/internal/scte35/crc_32.go b/internal/scte35/crc_32.go
@@ -17,9 +17,8 @@
 package scte35
 
 import (
+	"encoding/binary"
 	"errors"
-
-	"github.com/bamiaux/iobit"
 )
 
 // ErrCRC32Invalid indicates that a splice_info_sections CRC_32 is
@@ -304,13 +303,10 @@ func verifyCRC32(b []byte) error {
 		return ErrCRC32Invalid
 	}
 
-	r := iobit.NewReader(b)
-
-	payload := r.Bytes(len(b) - 4)
-	crc := r.Uint32(32)
-
-	calculated := calculateCRC32(payload)
-	if calculated != crc {
+	// crc32 is the last 4 bytes.
+	payload := b[:len(b)-4]
+	crc := binary.BigEndian.Uint32(b[len(b)-4:])
+	if calculateCRC32(payload) != crc {
 		return ErrCRC32Invalid
 	}
 
diff --git a/internal/scte35/scte35.go b/internal/scte35/scte35.go
@@ -22,8 +22,6 @@ import (
 	"errors"
 	"math"
 	"time"
-
-	"github.com/bamiaux/iobit"
 )
 
 const (
@@ -91,14 +89,3 @@ func TicksToDuration(ticks uint64) time.Duration {
 	s := float64(ticks) / float64(TicksPerSecond)
 	return time.Duration(int64(s * float64(time.Second)))
 }
-
-// readerError returns the readers error state, if any.
-func readerError(r iobit.Reader) error {
-	if r.LeftBits() > 0 {
-		return ErrBufferUnderflow
-	}
-	if errors.Is(r.Error(), iobit.ErrOverflow) {
-		return ErrBufferOverflow
-	}
-	return nil
-}