fix

encoding/codecv1/codecv1.go

@@ -388,9 +388,9 @@ func constructBlobPayload(chunks []*encoding.Chunk, useCompression bool) (*kzg48
 
 // makeBlobCanonical converts the raw blob data into the canonical blob representation of 4096 BLSFieldElements.
 func makeBlobCanonical(blobBytes []byte) (*kzg4844.Blob, error) {
-	// blob contains 131072 bytes but we can only utilize 31/32 of these
+	// blob contains 131072 bytes but we can only utilize 31/32 of these, which is 126976 bytes.
 	if len(blobBytes) > 124*1024 {
-		return nil, fmt.Errorf("oversized batch payload, blob bytes length: %v", len(blobBytes))
+		return nil, fmt.Errorf("oversized batch payload, blob bytes length: %v, max length: %v", len(blobBytes), 124*1024)
 	}
 
 	// the canonical (padded) blob payload