Merge pull request #233 from Eyevinn/fix-avc-slice-size

Fix avc slice size

CHANGELOG.md

@@ -9,7 +9,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
-- stpp box handles optional empty lists properly (a single zero byte)
+- `stpp` box handles optional empty lists properly (a single zero byte)
+- AVC slice size value
 
 ## [0.34.1] - 2023-03-09
 

avc/slice.go

@@ -346,11 +346,7 @@ func ParseSliceHeader(nalu []byte, spsMap map[uint32]*SPS, ppsMap map[uint32]*PP
 		sh.SliceGroupChangeCycle = uint32(r.Read(nrBits))
 	}
 
-	/* compute the size in bytes. Round up if not an integral number of bytes .*/
+	// compute the size in bytes. The last byte may not be fully read
 	sh.Size = uint32(r.NrBytesRead())
-	if r.NrBitsReadInCurrentByte() > 0 {
-		sh.Size++
-	}
-
 	return &sh, nil
 }

avc/slice_test.go

@@ -29,7 +29,7 @@ func TestParseSliceHeader(t *testing.T) {
 		SliceQPDelta:           6,
 		SliceAlphaC0OffsetDiv2: -3,
 		SliceBetaOffsetDiv2:    -3,
-		Size:                   8,
+		Size:                   7,
 	}
 	data, err := ioutil.ReadFile("testdata/blackframe.264")
 	if err != nil {

bits/aeebspreader.go

@@ -224,7 +224,7 @@ func (r *AccErrEBSPReader) ReadRbspTrailingBits() error {
 		return nil
 	}
 	if firstBit != 1 {
-		return fmt.Errorf("RbspTrailingBits don't start with 1")
+		return fmt.Errorf("rbspTrailingBits don't start with 1")
 	}
 	for {
 		b := r.Read(1)
@@ -236,7 +236,7 @@ func (r *AccErrEBSPReader) ReadRbspTrailingBits() error {
 			return nil
 		}
 		if b == 1 {
-			return fmt.Errorf("Another 1 in RbspTrailingBits")
+			return fmt.Errorf("another 1 in RbspTrailingBits")
 		}
 	}
 }

bits/aeebspreader_test.go

@@ -0,0 +1,49 @@
+package bits_test
+
+import (
+	"bytes"
+	"encoding/hex"
+	"testing"
+
+	"github.com/Eyevinn/mp4ff/bits"
+)
+
+func TestAccErrEBSPReader(t *testing.T) {
+	testCases := []struct {
+		hexData             string
+		readBits            int
+		expectedValue       uint
+		expectedNrBytesRead int
+		expectedNrBitsRead  int
+	}{
+		{"00", 0, 0, 0, 8},
+		{"0001", 1, 0, 1, 1},
+		{"0001", 8, 0x00, 1, 8},
+		{"0010", 12, 0x001, 2, 4},
+		{"0102", 16, 0x0102, 2, 8},
+		{"00000304", 24, 0x000004, 4, 8},
+	}
+	for _, tc := range testCases {
+		t.Run("", func(t *testing.T) {
+			data, err := hex.DecodeString(tc.hexData)
+			if err != nil {
+				t.Error(err)
+			}
+			buf := bytes.NewBuffer(data)
+			r := bits.NewAccErrEBSPReader(buf)
+			if r.AccError() != nil {
+				t.Errorf("expected no error, got %v", r.AccError())
+			}
+			v := r.Read(tc.readBits)
+			if v != tc.expectedValue {
+				t.Errorf("expected value %d, got %d", tc.expectedValue, v)
+			}
+			if r.NrBytesRead() != tc.expectedNrBytesRead {
+				t.Errorf("expected %d bytes read, got %d", tc.expectedNrBytesRead, r.NrBytesRead())
+			}
+			if r.NrBitsReadInCurrentByte() != tc.expectedNrBitsRead {
+				t.Errorf("expected %d bits read, got %d", tc.expectedNrBitsRead, r.NrBitsReadInCurrentByte())
+			}
+		})
+	}
+}