bits: rename WriteBits into WriteBitsUnsafe (#155)

bluenviron · Oct 20, 2024 · a1df134 · a1df134
1 parent 9cff2d7
commit a1df134
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Showing 4 changed files with 50 additions and 43 deletions.
diff --git a/pkg/bits/write.go b/pkg/bits/write.go
@@ -1,7 +1,14 @@
 package bits
 
 // WriteBits writes N bits.
+//
+// Deprecated: replaced by WriteBitsUnsafe.
 func WriteBits(buf []byte, pos *int, bits uint64, n int) {
+	WriteBitsUnsafe(buf, pos, bits, n)
+}
+
+// WriteBitsUnsafe writes N bits.
+func WriteBitsUnsafe(buf []byte, pos *int, bits uint64, n int) {
 	res := 8 - (*pos & 0x07)
 	if n < res {
 		buf[*pos>>0x03] |= byte(bits << (res - n))

diff --git a/pkg/bits/write_test.go b/pkg/bits/write_test.go
@@ -6,13 +6,13 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestWriteBits(t *testing.T) {
+func TestWriteBitsUnsafe(t *testing.T) {
 	buf := make([]byte, 6)
 	pos := 0
-	WriteBits(buf, &pos, uint64(0x2a), 6)
-	WriteBits(buf, &pos, uint64(0x0c), 6)
-	WriteBits(buf, &pos, uint64(0x1f), 6)
-	WriteBits(buf, &pos, uint64(0x5a), 8)
-	WriteBits(buf, &pos, uint64(0xaaec4), 20)
+	WriteBitsUnsafe(buf, &pos, uint64(0x2a), 6)
+	WriteBitsUnsafe(buf, &pos, uint64(0x0c), 6)
+	WriteBitsUnsafe(buf, &pos, uint64(0x1f), 6)
+	WriteBitsUnsafe(buf, &pos, uint64(0x5a), 8)
+	WriteBitsUnsafe(buf, &pos, uint64(0xaaec4), 20)
 	require.Equal(t, []byte{0xA8, 0xC7, 0xD6, 0xAA, 0xBB, 0x10}, buf)
 }
diff --git a/pkg/codecs/mpeg4audio/audio_specific_config.go b/pkg/codecs/mpeg4audio/audio_specific_config.go
@@ -202,17 +202,17 @@ func (c AudioSpecificConfig) Marshal() ([]byte, error) {
 
 func (c AudioSpecificConfig) marshalTo(buf []byte, pos *int) error {
 	if c.ExtensionType == ObjectTypeSBR || c.ExtensionType == ObjectTypePS {
-		bits.WriteBits(buf, pos, uint64(c.ExtensionType), 5)
+		bits.WriteBitsUnsafe(buf, pos, uint64(c.ExtensionType), 5)
 	} else {
-		bits.WriteBits(buf, pos, uint64(c.Type), 5)
+		bits.WriteBitsUnsafe(buf, pos, uint64(c.Type), 5)
 	}
 
 	sampleRateIndex, ok := reverseSampleRates[c.SampleRate]
 	if !ok {
-		bits.WriteBits(buf, pos, uint64(15), 4)
-		bits.WriteBits(buf, pos, uint64(c.SampleRate), 24)
+		bits.WriteBitsUnsafe(buf, pos, uint64(15), 4)
+		bits.WriteBitsUnsafe(buf, pos, uint64(c.SampleRate), 24)
 	} else {
-		bits.WriteBits(buf, pos, uint64(sampleRateIndex), 4)
+		bits.WriteBitsUnsafe(buf, pos, uint64(sampleRateIndex), 4)
 	}
 
 	var channelConfig int
@@ -226,33 +226,33 @@ func (c AudioSpecificConfig) marshalTo(buf []byte, pos *int) error {
 	default:
 		return fmt.Errorf("invalid channel count (%d)", c.ChannelCount)
 	}
-	bits.WriteBits(buf, pos, uint64(channelConfig), 4)
+	bits.WriteBitsUnsafe(buf, pos, uint64(channelConfig), 4)
 
 	if c.ExtensionType == ObjectTypeSBR || c.ExtensionType == ObjectTypePS {
 		sampleRateIndex, ok := reverseSampleRates[c.ExtensionSampleRate]
 		if !ok {
-			bits.WriteBits(buf, pos, uint64(0x0F), 4)
-			bits.WriteBits(buf, pos, uint64(c.ExtensionSampleRate), 24)
+			bits.WriteBitsUnsafe(buf, pos, uint64(0x0F), 4)
+			bits.WriteBitsUnsafe(buf, pos, uint64(c.ExtensionSampleRate), 24)
 		} else {
-			bits.WriteBits(buf, pos, uint64(sampleRateIndex), 4)
+			bits.WriteBitsUnsafe(buf, pos, uint64(sampleRateIndex), 4)
 		}
-		bits.WriteBits(buf, pos, uint64(c.Type), 5)
+		bits.WriteBitsUnsafe(buf, pos, uint64(c.Type), 5)
 	}
 
 	if c.FrameLengthFlag {
-		bits.WriteBits(buf, pos, 1, 1)
+		bits.WriteBitsUnsafe(buf, pos, 1, 1)
 	} else {
-		bits.WriteBits(buf, pos, 0, 1)
+		bits.WriteBitsUnsafe(buf, pos, 0, 1)
 	}
 
 	if c.DependsOnCoreCoder {
-		bits.WriteBits(buf, pos, 1, 1)
+		bits.WriteBitsUnsafe(buf, pos, 1, 1)
 	} else {
-		bits.WriteBits(buf, pos, 0, 1)
+		bits.WriteBitsUnsafe(buf, pos, 0, 1)
 	}
 
 	if c.DependsOnCoreCoder {
-		bits.WriteBits(buf, pos, uint64(c.CoreCoderDelay), 14)
+		bits.WriteBitsUnsafe(buf, pos, uint64(c.CoreCoderDelay), 14)
 	}
 
 	*pos++ // extensionFlag

diff --git a/pkg/codecs/mpeg4audio/stream_mux_config.go b/pkg/codecs/mpeg4audio/stream_mux_config.go
@@ -239,20 +239,20 @@ func (c StreamMuxConfig) Marshal() ([]byte, error) {
 	buf := make([]byte, c.marshalSize())
 	pos := 0
 
-	bits.WriteBits(buf, &pos, 0, 1) // audioMuxVersion
-	bits.WriteBits(buf, &pos, 1, 1) // allStreamsSameTimeFraming
-	bits.WriteBits(buf, &pos, uint64(c.NumSubFrames), 6)
-	bits.WriteBits(buf, &pos, uint64(len(c.Programs)-1), 4)
+	bits.WriteBitsUnsafe(buf, &pos, 0, 1) // audioMuxVersion
+	bits.WriteBitsUnsafe(buf, &pos, 1, 1) // allStreamsSameTimeFraming
+	bits.WriteBitsUnsafe(buf, &pos, uint64(c.NumSubFrames), 6)
+	bits.WriteBitsUnsafe(buf, &pos, uint64(len(c.Programs)-1), 4)
 
 	for prog, p := range c.Programs {
-		bits.WriteBits(buf, &pos, uint64(len(p.Layers)-1), 3)
+		bits.WriteBitsUnsafe(buf, &pos, uint64(len(p.Layers)-1), 3)
 
 		for lay, l := range p.Layers {
 			if prog != 0 || lay != 0 {
 				if l.AudioSpecificConfig != nil {
-					bits.WriteBits(buf, &pos, 0, 1)
+					bits.WriteBitsUnsafe(buf, &pos, 0, 1)
 				} else {
-					bits.WriteBits(buf, &pos, 1, 1)
+					bits.WriteBitsUnsafe(buf, &pos, 1, 1)
 				}
 			}
 
@@ -263,30 +263,30 @@ func (c StreamMuxConfig) Marshal() ([]byte, error) {
 				}
 			}
 
-			bits.WriteBits(buf, &pos, uint64(l.FrameLengthType), 3)
+			bits.WriteBitsUnsafe(buf, &pos, uint64(l.FrameLengthType), 3)
 
 			switch l.FrameLengthType {
 			case 0:
-				bits.WriteBits(buf, &pos, uint64(l.LatmBufferFullness), 8)
+				bits.WriteBitsUnsafe(buf, &pos, uint64(l.LatmBufferFullness), 8)
 
 			case 1:
-				bits.WriteBits(buf, &pos, uint64(l.FrameLength), 9)
+				bits.WriteBitsUnsafe(buf, &pos, uint64(l.FrameLength), 9)
 
 			case 4, 5, 3:
-				bits.WriteBits(buf, &pos, uint64(l.CELPframeLengthTableIndex), 6)
+				bits.WriteBitsUnsafe(buf, &pos, uint64(l.CELPframeLengthTableIndex), 6)
 
 			case 6, 7:
 				if l.HVXCframeLengthTableIndex {
-					bits.WriteBits(buf, &pos, 1, 1)
+					bits.WriteBitsUnsafe(buf, &pos, 1, 1)
 				} else {
-					bits.WriteBits(buf, &pos, 0, 1)
+					bits.WriteBitsUnsafe(buf, &pos, 0, 1)
 				}
 			}
 		}
 	}
 
 	if c.OtherDataPresent {
-		bits.WriteBits(buf, &pos, 1, 1)
+		bits.WriteBitsUnsafe(buf, &pos, 1, 1)
 
 		var lenBytes []byte
 		tmp := c.OtherDataLenBits
@@ -303,21 +303,21 @@ func (c StreamMuxConfig) Marshal() ([]byte, error) {
 		}
 
 		for i := len(lenBytes) - 1; i > 0; i-- {
-			bits.WriteBits(buf, &pos, 1, 1)
-			bits.WriteBits(buf, &pos, uint64(lenBytes[i]), 8)
+			bits.WriteBitsUnsafe(buf, &pos, 1, 1)
+			bits.WriteBitsUnsafe(buf, &pos, uint64(lenBytes[i]), 8)
 		}
 
-		bits.WriteBits(buf, &pos, 0, 1)
-		bits.WriteBits(buf, &pos, uint64(lenBytes[0]), 8)
+		bits.WriteBitsUnsafe(buf, &pos, 0, 1)
+		bits.WriteBitsUnsafe(buf, &pos, uint64(lenBytes[0]), 8)
 	} else {
-		bits.WriteBits(buf, &pos, 0, 1)
+		bits.WriteBitsUnsafe(buf, &pos, 0, 1)
 	}
 
 	if c.CRCCheckPresent {
-		bits.WriteBits(buf, &pos, 1, 1)
-		bits.WriteBits(buf, &pos, uint64(c.CRCCheckSum), 8)
+		bits.WriteBitsUnsafe(buf, &pos, 1, 1)
+		bits.WriteBitsUnsafe(buf, &pos, uint64(c.CRCCheckSum), 8)
 	} else {
-		bits.WriteBits(buf, &pos, 0, 1)
+		bits.WriteBitsUnsafe(buf, &pos, 0, 1)
 	}
 
 	return buf, nil