streaming

commit b43d09a3ddfbb8cb409c40c855531f1544b7f71c
parent ab15f9243df870d2643b2c31f6da896fe2adcec9
Author: Oliver Lowe <o@olowe.co>
Date:   Tue, 14 May 2024 18:07:47 +1000

scte35: More documentation

Needed docs on value of TimeSignal as it was unclear whether it
represented a duration or a timestamp (technically it's both but
semantically it's a timestamp). And an example function!

Diffstat:
A
scte35/codec_test.go
 | 
35
+++++++++++++++++++++++++++++++++++
M
scte35/command.go
 | 
4
+++-
M
scte35/scte35_test.go
 | 
2
--
M
scte35/splice_info.go
 | 
2
++

4 files changed, 40 insertions(+), 3 deletions(-)
diff --git a/scte35/codec_test.go b/scte35/codec_test.go
@@ -0,0 +1,35 @@
+package scte35_test
+
+import (
+	"encoding/base64"
+	"fmt"
+
+	"github.com/untangledco/streaming/scte35"
+)
+
+func Example() {
+	msg := "/DA0AAAAAAAA///wBQb+cr0AUAAeAhxDVUVJSAAAjn/PAAGlmbAICAAAAAAsoKGKNAIAmsnRfg=="
+	b, err := base64.StdEncoding.DecodeString(msg)
+	if err != nil {
+		// handle error...
+	}
+	splice, err := scte35.DecodeSpliceInfo(b)
+	if err != nil {
+		// handle error...
+	}
+
+	dur := splice.Descriptors[0].(scte35.SegmentationDescriptor).Duration
+	fmt.Println(*dur)
+	*dur += 15 * 90000 // add 15 seconds as per 90KHz clock.
+	fmt.Println(*splice.Descriptors[0].(scte35.SegmentationDescriptor).Duration)
+
+	bb, err := scte35.EncodeSpliceInfo(splice)
+	if err != nil {
+		// handle error...
+	}
+	fmt.Println(base64.StdEncoding.EncodeToString(bb))
+
+	// Output: 27630000
+	// 28980000
+	// /DA0AAAAAAAA///wBQb+cr0AUAAeAhxDVUVJSAAAjn/PAAG6MyAICAAAAAAsoKGKNAIAQO/SuQ==
+}
diff --git a/scte35/command.go b/scte35/command.go
@@ -15,7 +15,9 @@ type Command struct {
 	Type     CommandType
 	Schedule []Event // SpliceSchedule
 	Insert   *Insert
-	// Number of ticks of a 90KHz clock.
+	// Number of ticks of a 90KHz clock since midnight UTC.
+	// TODO(otl): use time.Time here instead,
+	// then calculate ticks when converting to wire format?
 	TimeSignal *uint64
 	Private    *PrivateCommand
 }
diff --git a/scte35/scte35_test.go b/scte35/scte35_test.go
@@ -168,5 +168,3 @@ var samples = []sample{
 		},
 	},
 }
-
-func newuint64(i uint64) *uint64 { p := new(uint64); p = &i; return p }
diff --git a/scte35/splice_info.go b/scte35/splice_info.go
@@ -263,3 +263,5 @@ func decodeCommand(buf []byte) (*Command, error) {
 	}
 	return &cmd, nil
 }
+
+func newuint64(i uint64) *uint64 { p := new(uint64); p = &i; return p }